부산대학교 도서관

Bline KE; Center for Vaccines and Immunity, Nationwide Children's Hospital, Columbus, OH, USA. Katherine.Bline@nationwidechildrens.org.; Division of Critical Care Medicine, Nationwide Children's Hospital, Columbus, OH, USA. Katherine.Bline@nationwidechildrens.org.

Publisher: Nature Publishing Group Country of Publication: United States NLM ID: 0100714 Publication Model: Print-Electronic Cited Medium: Internet ISSN: 1530-0447 (Electronic) Linking ISSN: 00313998 NLM ISO Abbreviation: Pediatr Res Subsets: MEDLINE

Wells J; Department of Pediatrics, Division of Emergency Medicine, Nationwide Children's Hospital, The Ohio State University College of Medicine, Columbus, OH, United States.; Shah A; Division of Hospital Medicine, Cincinnati Children's Hospital Medical Center, Cincinnati, OH, United States.; Gillis H; Department of Anesthesiology, Division of Pediatric Anesthestiology, University of Minnesota, Minneapolis, MN, United States.; Gustafson S; Division of Pediatric Hospital Medicine, Harbor-UCLA Medical Center, David Geffen School of Medicine at UCLA, Los Angeles, CA, United States.; Powell C; Division of Pediatric Hospital Medicine, Stanford University School of Medicine, Stanford, CA, United States.; Krasaelap A; Department of Gastroenterology and Hepatology, SeattleChildren's Hospital, Seattle, WA, United States.; Hanna S; Saint Louis University School of Medicine, SSM Health Cardinal Glennon Children's Hospital, St. Louis, MO, United States.; Hoefert JA; Saint Louis University School of Medicine, SSM Health Cardinal Glennon Children's Hospital, St. Louis, MO, United States.; Bigelow A; The Heart Center, Nationwide Children's Hospital, Columbus, OH, United States.; Sherwin J; Division of Cardiovascular and Thoracic Surgery,Duke University Medical Center, Durham, NC, United States.; Lewis EC; Division of Hospital Pediatrics, Department of Pediatrics,University of North Carolina School of Medicine, Chapel Hill, NC, United States.; Bline KE; Division of Critical Care Medicine, Department of Pediatrics, Nationwide Children's Hospital, The Ohio State University College of Medicine, Columbus, OH, United States.

Publisher: Frontiers Editorial Office Country of Publication: Switzerland NLM ID: 101616579 Publication Model: eCollection Cited Medium: Internet ISSN: 2296-2565 (Electronic) Linking ISSN: 22962565 NLM ISO Abbreviation: Front Public Health Subsets: MEDLINE

Zambrano LD; Newhams MM; Simeone RM; Payne AB; Wu M; Orzel-Lockwood AO; Halasa NB; Calixte JM; Pannaraj PS; Mongkolrattanothai K; Boom JA; Sahni LC; Kamidani S; Chiotos K; Cameron MA; Maddux AB; Irby K; Schuster JE; Mack EH; Biggs A; Coates BM; Michelson KN; Bline KE; Nofziger RA; Crandall H; Hobbs CV; Gertz SJ; Heidemann SM; Bradford TT; Walker TC; Schwartz SP; Staat MA; Bhumbra SS; Hume JR; Kong M; Stockwell MS; Connors TJ; Cullimore ML; Flori HR; Levy ER; Cvijanovich NZ; Zinter MS; Maamari M; Bowens C; Zerr DM; Guzman-Cottrill JA; Gonzalez I; Campbell AP; Randolph AG

Publisher: U.S. Centers for Disease Control Country of Publication: United States NLM ID: 7802429 Publication Model: Electronic Cited Medium: Internet ISSN: 1545-861X (Electronic) Linking ISSN: 01492195 NLM ISO Abbreviation: MMWR Morb Mortal Wkly Rep Subsets: MEDLINE

Simeone RM; Zambrano LD; Halasa NB; Fleming-Dutra KE; Newhams MM; Wu MJ; Orzel-Lockwood AO; Kamidani S; Pannaraj PS; Irby K; Maddux AB; Hobbs CV; Cameron MA; Boom JA; Sahni LC; Kong M; Nofziger RA; Schuster JE; Crandall H; Hume JR; Staat MA; Mack EH; Bradford TT; Heidemann SM; Levy ER; Gertz SJ; Bhumbra SS; Walker TC; Bline KE; Michelson KN; Zinter MS; Flori HR; Campbell AP; Randolph AG

Publisher: U.S. Centers for Disease Control Country of Publication: United States NLM ID: 7802429 Publication Model: Electronic Cited Medium: Internet ISSN: 1545-861X (Electronic) Linking ISSN: 01492195 NLM ISO Abbreviation: MMWR Morb Mortal Wkly Rep Subsets: MEDLINE

Zambrano LD; CDC COVID-19 Response Team, Atlanta, Georgia, USA.; Newhams MM; Department of Anesthesiology, Critical Care, and Pain Medicine, Boston Children's Hospital, Boston, Massachusetts, USA.; Olson SM; CDC COVID-19 Response Team, Atlanta, Georgia, USA.; Halasa NB; Division of Pediatric Infectious Diseases, Department of Pediatrics, Vanderbilt University Medical Center, Nashville, Tennessee, USA.; Price AM; CDC COVID-19 Response Team, Atlanta, Georgia, USA.; Orzel AO; Department of Anesthesiology, Critical Care, and Pain Medicine, Boston Children's Hospital, Boston, Massachusetts, USA.; Young CC; Department of Anesthesiology, Critical Care, and Pain Medicine, Boston Children's Hospital, Boston, Massachusetts, USA.; Boom JA; Department of Pediatrics, Baylor College of Medicine, Immunization Project, Texas Children's Hospital, Houston, Texas, USA.; Sahni LC; Department of Pediatrics, Baylor College of Medicine, Immunization Project, Texas Children's Hospital, Houston, Texas, USA.; Maddux AB; Department of Pediatrics, Section of Critical Care Medicine, University of Colorado School of Medicine and Children's Hospital Colorado, Aurora, Colorado, USA.; Bline KE; Division of Pediatric Critical Care Medicine, Nationwide Children's Hospital, Columbus, Ohio, USA.; Kamidani S; The Center for Childhood Infections and Vaccines of Children's Healthcare of Atlanta and the Department of Pediatrics, Emory University School of Medicine, Atlanta, Georgia, USA.; Tarquinio KM; Division of Critical Care Medicine, Department of Pediatrics, Emory University School of Medicine, Children's Healthcare of Atlanta, Atlanta, Georgia, USA.; Chiotos K; Division of Critical Care Medicine, Department of Anesthesiology and Critical Care, Children's Hospital of Philadelphia, Philadelphia, Pennsylvania, USA.; Schuster JE; Division of Pediatric Infectious Diseases, Department of Pediatrics, Children's Mercy Kansas City, Kansas City, Missouri, USA.; Cullimore ML; Division of Pediatric Critical Care, Department of Pediatrics, Children's Hospital and Medical Center, Omaha, Nebraska, USA.; Heidemann SM; Division of Pediatric Critical Care Medicine, Children's Hospital of Michigan, Central Michigan University, Detroit, Michigan, USA.; Hobbs CV; Division of Infectious Diseases, Department of Pediatrics, University of Mississippi Medical Center, Jackson, Mississippi, USA.; Nofziger RA; Division of Critical Care Medicine, Department of Pediatrics, Akron Children's Hospital, Akron, Ohio, USA.; Pannaraj PS; Division of Infectious Diseases, Children's Hospital Los Angeles and Departments of Pediatrics and Molecular Microbiology and Immunology, University of Southern California, Los Angeles, California, USA.; Cameron MA; Division of Pediatric Hospital Medicine, UC San Diego-Rady Children's Hospital, San Diego, California, USA.; Walker TC; Department of Pediatrics, University of North Carolina at Chapel Hill Children's Hospital, Chapel Hill, North Carolina, USA.; Schwartz SP; Department of Pediatrics, University of North Carolina at Chapel Hill Children's Hospital, Chapel Hill, North Carolina, USA.; Michelson KN; Division of Critical Care Medicine, Department of Pediatrics, Northwestern University Feinberg School of Medicine, Ann & Robert H. Lurie Children's Hospital of Chicago, Chicago, Illinois, USA.; Coates BM; Division of Critical Care Medicine, Department of Pediatrics, Northwestern University Feinberg School of Medicine, Ann & Robert H. Lurie Children's Hospital of Chicago, Chicago, Illinois, USA.; Flori HR; Division of Pediatric Critical Care Medicine, Department of Pediatrics, Mott Children's Hospital and University of Michigan, Ann Arbor, Michigan, USA.; Mack EH; Division of Pediatric Critical Care Medicine, Medical University of South Carolina, Charleston, South Carolina, USA.; Smallcomb L; Department of Pediatrics, Medical University of South Carolina, Charleston, South Carolina, USA.; Gertz SJ; Division of Pediatric Critical Care, Department of Pediatrics, Cooperman Barnabas Medical Center, Livingston, New Jersey, USA.; Bhumbra SS; The Ryan White Center for Pediatric Infectious Disease and Global Health, Department of Pediatrics, Indiana University School of Medicine, Indianapolis, Indiana, USA.; Bradford TT; Division of Cardiology, Department of Pediatrics, Louisiana State University Health Sciences Center and Children's Hospital of New Orleans, New Orleans, Louisiana, USA.; Levy ER; Divisions of Pediatric Infectious Diseases and Pediatric Critical Care Medicine, Department of Pediatric and Adolescent Medicine, Mayo Clinic, Rochester, Minnesota, USA.; Kong M; Division of Pediatric Critical Care Medicine, Department of Pediatrics, University of Alabama at Birmingham, Birmingham, Alabama, USA.; Irby K; Section of Pediatric Critical Care, Department of Pediatrics, Arkansas Children's Hospital, Little Rock, Arkansas, USA.; Cvijanovich NZ; Division of Critical Care Medicine, UCSF Benioff Children's Hospital, Oakland, California, USA.; Zinter MS; Divisions of Critical Care Medicine and Allergy, Immunology, and Bone Marrow Transplant, Department of Pediatrics, University of California, San Francisco, San Francisco, California, USA.; Bowens C; Department of Pediatrics, Division of Critical Care Medicine, University of Texas Southwestern, Children's Medical Center, Dallas, Texas, USA.; Crandall H; Division of Pediatric Critical Care, Department of Pediatrics, University of Utah, Salt Lake City, Utah, USA.; Hume JR; Division of Pediatric Critical Care, University of Minnesota Masonic Children's Hospital, Minneapolis, Minnesota, USA.; Patel MM; CDC COVID-19 Response Team, Atlanta, Georgia, USA.; Campbell AP; CDC COVID-19 Response Team, Atlanta, Georgia, USA.; Randolph AG; Department of Anesthesiology, Critical Care, and Pain Medicine, Boston Children's Hospital, Boston, Massachusetts, USA.; Departments of Anesthesia and Pediatrics, Harvard Medical School, Boston, Massachusetts, USA.

Publisher: Oxford University Press Country of Publication: United States NLM ID: 9203213 Publication Model: Print Cited Medium: Internet ISSN: 1537-6591 (Electronic) Linking ISSN: 10584838 NLM ISO Abbreviation: Clin Infect Dis Subsets: MEDLINE

Zambrano LD; From the Coronavirus and Other Respiratory Viruses Division, Centers for Disease Control and Prevention, Atlanta, Georgia.; Newhams MM; Department of Anesthesiology, Critical Care, and Pain Medicine, Boston Children's Hospital, Boston, Massachusetts.; Simeone RM; From the Coronavirus and Other Respiratory Viruses Division, Centers for Disease Control and Prevention, Atlanta, Georgia.; Fleming-Dutra KE; From the Coronavirus and Other Respiratory Viruses Division, Centers for Disease Control and Prevention, Atlanta, Georgia.; Halasa N; Division of Pediatric Infectious Diseases, Department of Pediatrics, Vanderbilt University Medical Center, Nashville, Tennessee.; Wu M; From the Coronavirus and Other Respiratory Viruses Division, Centers for Disease Control and Prevention, Atlanta, Georgia.; Orzel-Lockwood AO; Department of Anesthesiology, Critical Care, and Pain Medicine, Boston Children's Hospital, Boston, Massachusetts.; Kamidani S; The Center for Childhood Infections and Vaccines of Children's Healthcare of Atlanta and the Department of Pediatrics, Emory University School of Medicine, Atlanta, Georgia.; Pannaraj PS; Division of Infectious Diseases, Departments of Pediatrics and Molecular Microbiology and Immunology, University of Southern California, Children's Hospital Los Angeles, Los Angeles, California.; Chiotos K; Division of Critical Care Medicine, Department of Anesthesiology and Critical Care, Children's Hospital of Philadelphia, Philadelphia, Pennsylvania.; Cameron MA; Division of Pediatric Hospital Medicine, UC San Diego-Rady Children's Hospital, San Diego, California.; Maddux AB; Department of Pediatrics, Section of Critical Care Medicine, University of Colorado School of Medicine and Children's Hospital Colorado, Aurora, Colorado.; Schuster JE; Division of Pediatric Infectious Diseases, Department of Pediatrics, Children's Mercy Kansas City, Kansas City, Missouri.; Crandall H; Division of Pediatric Critical Care, Department of Pediatrics, University of Utah and Primary Children's Hospital, Salt Lake City, Utah.; Kong M; Division of Pediatric Critical Care Medicine, Department of Pediatrics, University of Alabama at Birmingham, Birmingham, Alabama.; Nofziger RA; Division of Critical Care Medicine, Department of Pediatrics, Akron Children's Hospital, Akron, Ohio.; Staat MA; Department of Pediatrics, University of Cincinnati College of Medicine, Cincinnati Children's Hospital Medical Center, Cincinnati, Ohio.; Bhumbra SS; Department of Pediatrics, The Ryan White Center for Pediatric Infectious Disease and Global Health, Indiana University School of Medicine, Indianapolis, Indiana.; Irby K; Section of Pediatric Critical Care, Department of Pediatrics, Arkansas Children's Hospital, Little Rock, Arkansas.; Boom JA; Department of Pediatrics, Baylor College of Medicine, Immunization Project, Texas Children's Hospital, Houston, Texas.; Sahni LC; Department of Pediatrics, Baylor College of Medicine, Immunization Project, Texas Children's Hospital, Houston, Texas.; Hume JR; Division of Pediatric Critical Care, University of Minnesota Masonic Children's Hospital, Minneapolis, Minnesota.; Gertz SJ; Division of Pediatric Critical Care, Department of Pediatrics, Cooperman Barnabas Medical Center, Livingston, New Jersey.; Maamari M; Department of Pediatrics, Division of Critical Care Medicine, University of Texas Southwestern, Children's Medical Center Dallas, Texas.; Bowens C; Department of Pediatrics, Division of Critical Care Medicine, University of Texas Southwestern, Children's Medical Center Dallas, Texas.; Levy ER; Divisions of Pediatric Infectious Diseases and Pediatric Critical Care Medicine, Department of Pediatric and Adolescent Medicine, Mayo Clinic, Rochester, Minnesota.; Bradford TT; Division of Cardiology, Department of Pediatrics, Louisiana State University Health Sciences Center and Children's Hospital of New Orleans, New Orleans, Louisiana.; Walker TC; Department of Pediatrics, University of North Carolina at Chapel Hill Children's Hospital, Chapel Hill, North Carolina.; Schwartz SP; Department of Pediatrics, University of North Carolina at Chapel Hill Children's Hospital, Chapel Hill, North Carolina.; Mack EH; Division of Pediatric Critical Care Medicine, Medical University of South Carolina, Charleston, South Carolina.; Guzman-Cottrill JA; Division of Infectious Diseases, Department of Pediatrics, Oregon Health and Science University, Portland, Oregon.; Hobbs CV; Division of Infectious Diseases, Department of Pediatrics, and Department of Cell and Molecular Biology, Children's of Mississippi, University of Mississippi Medical Center, Jackson, Mississippi.; Zinter MS; Divisions of Critical Care Medicine and Allergy, Immunology, and Bone Marrow Transplant, Department of Pediatrics, University of California San Francisco, San Francisco, California.; Cvijanovich NZ; Division of Critical Care Medicine, UCSF Benioff Children's Hospital Oakland, California.; Bline KE; Division of Pediatric Critical Care Medicine, Nationwide Children's Hospital Columbus, Ohio.; Hymes SR; Division of Pediatric Infectious Diseases, Department of Pediatrics, Bernard and Millie Duker Children's Hospital, Albany Med Health System, Albany, New York.; Campbell AP; From the Coronavirus and Other Respiratory Viruses Division, Centers for Disease Control and Prevention, Atlanta, Georgia.; Randolph AG; Department of Anesthesiology, Critical Care, and Pain Medicine, Boston Children's Hospital, Boston, Massachusetts.; Departments of Anaesthesia and Pediatrics, Harvard Medical School, Boston, Massachusetts, USA.; Department of Pediatrics, Harvard Medical School, Boston, Massachusetts.

Publisher: Williams & Wilkins Country of Publication: United States NLM ID: 8701858 Publication Model: Print-Electronic Cited Medium: Internet ISSN: 1532-0987 (Electronic) Linking ISSN: 08913668 NLM ISO Abbreviation: Pediatr Infect Dis J Subsets: MEDLINE

Halasa NB; Olson SM; Staat MA; Newhams MM; Price AM; Boom JA; Sahni LC; Cameron MA; Pannaraj PS; Bline KE; Bhumbra SS; Bradford TT; Chiotos K; Coates BM; Cullimore ML; Cvijanovich NZ; Flori HR; Gertz SJ; Heidemann SM; Hobbs CV; Hume JR; Irby K; Kamidani S; Kong M; Levy ER; Mack EH; Maddux AB; Michelson KN; Nofziger RA; Schuster JE; Schwartz SP; Smallcomb L; Tarquinio KM; Walker TC; Zinter MS; Gilboa SM; Polen KN; Campbell AP; Randolph AG; Patel MM

Publisher: U.S. Centers for Disease Control Country of Publication: United States NLM ID: 7802429 Publication Model: Electronic Cited Medium: Internet ISSN: 1545-861X (Electronic) Linking ISSN: 01492195 NLM ISO Abbreviation: MMWR Morb Mortal Wkly Rep Subsets: MEDLINE

Zambrano LD; Newhams MM; Olson SM; Halasa NB; Price AM; Boom JA; Sahni LC; Kamidani S; Tarquinio KM; Maddux AB; Heidemann SM; Bhumbra SS; Bline KE; Nofziger RA; Hobbs CV; Bradford TT; Cvijanovich NZ; Irby K; Mack EH; Cullimore ML; Pannaraj PS; Kong M; Walker TC; Gertz SJ; Michelson KN; Cameron MA; Chiotos K; Maamari M; Schuster JE; Orzel AO; Patel MM; Campbell AP; Randolph AG

Publisher: U.S. Centers for Disease Control Country of Publication: United States NLM ID: 7802429 Publication Model: Electronic Cited Medium: Internet ISSN: 1545-861X (Electronic) Linking ISSN: 01492195 NLM ISO Abbreviation: MMWR Morb Mortal Wkly Rep Subsets: MEDLINE

Bline KE; Center for Vaccines and Immunity, Nationwide Children's Hospital, Columbus, OH, USA. Katherine.Bline@nationwidechildrens.org.; Division of Critical Care Medicine, Nationwide Children's Hospital, Columbus, OH, USA. Katherine.Bline@nationwidechildrens.org.; Wilt AL; Center for Vaccines and Immunity, Nationwide Children's Hospital, Columbus, OH, USA.; Alexander RN; Biostatistics Resource at Nationwide Children's Hospital, Columbus, OH, USA.; Andrews AN; Center for Vaccines and Immunity, Nationwide Children's Hospital, Columbus, OH, USA.; Mertz SE; Center for Vaccines and Immunity, Nationwide Children's Hospital, Columbus, OH, USA.; Ye F; Abigail Wexner Research Institute, Nationwide Children's Hospital, Columbus, OH, USA.; Steele LM; Division of Critical Care Medicine, Nationwide Children's Hospital, Columbus, OH, USA.; Wolfe AL; Division of Critical Care Medicine, Nationwide Children's Hospital, Columbus, OH, USA.; Mejias A; Department of Infectious Disease, St. Jude Children's Research Hospital, Memphis, TN, USA.; Ramilo O; Department of Infectious Disease, St. Jude Children's Research Hospital, Memphis, TN, USA.

Publisher: Nature Publishing Group Country of Publication: United States NLM ID: 0100714 Publication Model: Print-Electronic Cited Medium: Internet ISSN: 1530-0447 (Electronic) Linking ISSN: 00313998 NLM ISO Abbreviation: Pediatr Res Subsets: MEDLINE

Bline KE; Division of Critical Care Medicine, Department of Pediatrics, Nationwide Children's Hospital, Columbus, OH 43205, USA.; Hall MW; Division of Critical Care Medicine, Department of Pediatrics, Nationwide Children's Hospital, Columbus, OH 43205, USA.

Publisher: MDPI AG Country of Publication: Switzerland NLM ID: 101596317 Publication Model: Electronic Cited Medium: Print ISSN: 2076-0817 (Print) Linking ISSN: 20760817 NLM ISO Abbreviation: Pathogens Subsets: PubMed not MEDLINE

Bline KE; The Abigail Wexner Research Institute at Nationwide Children's Hospital, Columbus, OH, USA. katherine.bline@nationwidechildrens.org.; Division of Critical Care Medicine, Nationwide Children's Hospital, 700 Children's Drive, Columbus, OH, 43205, USA. katherine.bline@nationwidechildrens.org.; Moore-Clingenpeel M; The Abigail Wexner Research Institute at Nationwide Children's Hospital, Columbus, OH, USA.; Biostatistics Resource at Nationwide Children's Hospital, Columbus, OH, USA.; Hensley J; The Abigail Wexner Research Institute at Nationwide Children's Hospital, Columbus, OH, USA.; Steele L; The Abigail Wexner Research Institute at Nationwide Children's Hospital, Columbus, OH, USA.; Greathouse K; The Abigail Wexner Research Institute at Nationwide Children's Hospital, Columbus, OH, USA.; Anglim L; The Abigail Wexner Research Institute at Nationwide Children's Hospital, Columbus, OH, USA.; Hanson-Huber L; The Abigail Wexner Research Institute at Nationwide Children's Hospital, Columbus, OH, USA.; Nateri J; The Abigail Wexner Research Institute at Nationwide Children's Hospital, Columbus, OH, USA.; Muszynski JA; The Abigail Wexner Research Institute at Nationwide Children's Hospital, Columbus, OH, USA.; Division of Critical Care Medicine, Nationwide Children's Hospital, 700 Children's Drive, Columbus, OH, 43205, USA.; Ramilo O; The Abigail Wexner Research Institute at Nationwide Children's Hospital, Columbus, OH, USA.; Division of Infectious Diseases, Nationwide Children's Hospital, Columbus, OH, USA.; Hall MW; The Abigail Wexner Research Institute at Nationwide Children's Hospital, Columbus, OH, USA.; Division of Critical Care Medicine, Nationwide Children's Hospital, 700 Children's Drive, Columbus, OH, 43205, USA.

Publisher: BioMed Central Ltd Country of Publication: England NLM ID: 9801902 Publication Model: Electronic Cited Medium: Internet ISSN: 1466-609X (Electronic) Linking ISSN: 13648535 NLM ISO Abbreviation: Crit Care Subsets: MEDLINE

Halasa NB; From the Division of Pediatric Infectious Diseases, Department of Pediatrics, Vanderbilt University Medical Center, Nashville (N.B.H.); the Covid-19 Response Team, Centers for Disease Control and Prevention (S.M.O., A.M.P., S.M.G., K.N.P., A.P.C., M.M.P.), the Center for Childhood Infections and Vaccines of Children's Healthcare of Atlanta and the Department of Pediatrics, Emory University School of Medicine (S.K.), and the Division of Critical Care Medicine, Department of Pediatrics, Emory University School of Medicine, Children's Healthcare of Atlanta (K.M.T.) - all in Atlanta; the Department of Pediatrics, University of Cincinnati College of Medicine, Cincinnati Children's Hospital Medical Center, Cincinnati (M.A.S.), the Division of Pediatric Critical Care Medicine, Nationwide Children's Hospital, Columbus (K.E.B.), and the Division of Critical Care Medicine, Department of Pediatrics, Akron Children's Hospital, Akron (R.A.N.) - all in Ohio; the Department of Anesthesiology, Critical Care, and Pain Medicine, Boston Children's Hospital (M.M.N., A.G.R.), and the Departments of Anaesthesia and Pediatrics, Harvard Medical School (A.G.R.) - both in Boston; the Division of Infectious Diseases, Children's Hospital Los Angeles, and the Departments of Pediatrics and Molecular Microbiology and Immunology, University of Southern California, Los Angeles, Los Angeles (P.S.P.), the Division of Pediatric Hospital Medicine, UC San Diego-Rady Children's Hospital, San Diego (M.A.C.), the Department of Pediatrics, Divisions of Critical Care Medicine and Allergy, Immunology, and Bone Marrow Transplant, University of California, San Francisco, San Francisco (M.S.Z.), and the Division of Critical Care Medicine, UCSF Benioff Children's Hospital, Oakland (N.Z.C.) - all in California; the Department of Pediatrics, Baylor College of Medicine, Immunization Project, Texas Children's Hospital, Houston (J.A.B., L.C.S.); the Division of Critical Care Medicine, Department of Anesthesiology and Critical Care, Children's Hospital of Philadelphia, Philadelphia (K.C.); the Department of Pediatrics, Division of Infectious Diseases, University of Mississippi Medical Center, Jackson (C.V.H.); the Department of Pediatrics, Section of Critical Care Medicine, University of Colorado School of Medicine, and Children's Hospital Colorado, Aurora (A.B.M.); the Division of Critical Care Medicine, Department of Pediatrics, Northwestern University Feinberg School of Medicine, Ann and Robert H. Lurie Children's Hospital of Chicago, Chicago (B.M.C., K.N.M.); the Division of Pediatric Critical Care Medicine, Children's Hospital of Michigan, Central Michigan University, Detroit (S.M.H.), and the Division of Pediatric Critical Care Medicine, Department of Pediatrics, Mott Children's Hospital and University of Michigan, Ann Arbor (H.R.F.); the Section of Pediatric Critical Care, Department of Pediatrics, Arkansas Children's Hospital, Little Rock (K.I.); the Division of Pediatric Critical Care Medicine (E.H.M.), and the Department of Pediatrics (L.S.), Medical University of South Carolina, Charleston; the Department of Pediatrics, University of North Carolina at Chapel Hill Children's Hospital, Chapel Hill (S.P.S., T.C.W.); the Division of Pediatric Critical Care, Department of Pediatrics, Cooperman Barnabas Medical Center, Livingston, NJ (S.J.G.); the Division of Pediatric Infectious Diseases, Department of Pediatrics, Children's Mercy Kansas City, Kansas City, Missouri (J.E.S.); the Ryan White Center for Pediatric Infectious Disease and Global Health, Department of Pediatrics, Indiana University School of Medicine, Indianapolis (S.S.B.); the Department of Pediatrics, Division of Critical Care Medicine, University of Texas Southwestern, Children's Medical Center, Dallas (M.M.); the Division of Pediatric Critical Care, University of Minnesota Masonic Children's Hospital, Minneapolis (J.R.H.), and the Divisions of Pediatric Infectious Diseases and Pediatric Critical Care Medicine, Department of Pediatric and Adolescent Medicine, Mayo Clinic, Rochester (E.R.L.) - both in Minnesota; the Division of Pediatric Critical Care, Department of Pediatrics, University of Utah, Salt Lake City (H.C.); the Department of Pediatrics, Division of Cardiology, Louisiana State University Health Sciences Center and Children's Hospital of New Orleans, New Orleans (T.T.B.); the Division of Pediatric Critical Care, Department of Pediatrics, Children's Hospital and Medical Center, Omaha, NE (M.L.C.); and the Division of Pediatric Critical Care Medicine, Department of Pediatrics, University of Alabama at Birmingham, Birmingham (M.K.).; Olson SM; From the Division of Pediatric Infectious Diseases, Department of Pediatrics, Vanderbilt University Medical Center, Nashville (N.B.H.); the Covid-19 Response Team, Centers for Disease Control and Prevention (S.M.O., A.M.P., S.M.G., K.N.P., A.P.C., M.M.P.), the Center for Childhood Infections and Vaccines of Children's Healthcare of Atlanta and the Department of Pediatrics, Emory University School of Medicine (S.K.), and the Division of Critical Care Medicine, Department of Pediatrics, Emory University School of Medicine, Children's Healthcare of Atlanta (K.M.T.) - all in Atlanta; the Department of Pediatrics, University of Cincinnati College of Medicine, Cincinnati Children's Hospital Medical Center, Cincinnati (M.A.S.), the Division of Pediatric Critical Care Medicine, Nationwide Children's Hospital, Columbus (K.E.B.), and the Division of Critical Care Medicine, Department of Pediatrics, Akron Children's Hospital, Akron (R.A.N.) - all in Ohio; the Department of Anesthesiology, Critical Care, and Pain Medicine, Boston Children's Hospital (M.M.N., A.G.R.), and the Departments of Anaesthesia and Pediatrics, Harvard Medical School (A.G.R.) - both in Boston; the Division of Infectious Diseases, Children's Hospital Los Angeles, and the Departments of Pediatrics and Molecular Microbiology and Immunology, University of Southern California, Los Angeles, Los Angeles (P.S.P.), the Division of Pediatric Hospital Medicine, UC San Diego-Rady Children's Hospital, San Diego (M.A.C.), the Department of Pediatrics, Divisions of Critical Care Medicine and Allergy, Immunology, and Bone Marrow Transplant, University of California, San Francisco, San Francisco (M.S.Z.), and the Division of Critical Care Medicine, UCSF Benioff Children's Hospital, Oakland (N.Z.C.) - all in California; the Department of Pediatrics, Baylor College of Medicine, Immunization Project, Texas Children's Hospital, Houston (J.A.B., L.C.S.); the Division of Critical Care Medicine, Department of Anesthesiology and Critical Care, Children's Hospital of Philadelphia, Philadelphia (K.C.); the Department of Pediatrics, Division of Infectious Diseases, University of Mississippi Medical Center, Jackson (C.V.H.); the Department of Pediatrics, Section of Critical Care Medicine, University of Colorado School of Medicine, and Children's Hospital Colorado, Aurora (A.B.M.); the Division of Critical Care Medicine, Department of Pediatrics, Northwestern University Feinberg School of Medicine, Ann and Robert H. Lurie Children's Hospital of Chicago, Chicago (B.M.C., K.N.M.); the Division of Pediatric Critical Care Medicine, Children's Hospital of Michigan, Central Michigan University, Detroit (S.M.H.), and the Division of Pediatric Critical Care Medicine, Department of Pediatrics, Mott Children's Hospital and University of Michigan, Ann Arbor (H.R.F.); the Section of Pediatric Critical Care, Department of Pediatrics, Arkansas Children's Hospital, Little Rock (K.I.); the Division of Pediatric Critical Care Medicine (E.H.M.), and the Department of Pediatrics (L.S.), Medical University of South Carolina, Charleston; the Department of Pediatrics, University of North Carolina at Chapel Hill Children's Hospital, Chapel Hill (S.P.S., T.C.W.); the Division of Pediatric Critical Care, Department of Pediatrics, Cooperman Barnabas Medical Center, Livingston, NJ (S.J.G.); the Division of Pediatric Infectious Diseases, Department of Pediatrics, Children's Mercy Kansas City, Kansas City, Missouri (J.E.S.); the Ryan White Center for Pediatric Infectious Disease and Global Health, Department of Pediatrics, Indiana University School of Medicine, Indianapolis (S.S.B.); the Department of Pediatrics, Division of Critical Care Medicine, University of Texas Southwestern, Children's Medical Center, Dallas (M.M.); the Division of Pediatric Critical Care, University of Minnesota Masonic Children's Hospital, Minneapolis (J.R.H.), and the Divisions of Pediatric Infectious Diseases and Pediatric Critical Care Medicine, Department of Pediatric and Adolescent Medicine, Mayo Clinic, Rochester (E.R.L.) - both in Minnesota; the Division of Pediatric Critical Care, Department of Pediatrics, University of Utah, Salt Lake City (H.C.); the Department of Pediatrics, Division of Cardiology, Louisiana State University Health Sciences Center and Children's Hospital of New Orleans, New Orleans (T.T.B.); the Division of Pediatric Critical Care, Department of Pediatrics, Children's Hospital and Medical Center, Omaha, NE (M.L.C.); and the Division of Pediatric Critical Care Medicine, Department of Pediatrics, University of Alabama at Birmingham, Birmingham (M.K.).; Staat MA; From the Division of Pediatric Infectious Diseases, Department of Pediatrics, Vanderbilt University Medical Center, Nashville (N.B.H.); the Covid-19 Response Team, Centers for Disease Control and Prevention (S.M.O., A.M.P., S.M.G., K.N.P., A.P.C., M.M.P.), the Center for Childhood Infections and Vaccines of Children's Healthcare of Atlanta and the Department of Pediatrics, Emory University School of Medicine (S.K.), and the Division of Critical Care Medicine, Department of Pediatrics, Emory University School of Medicine, Children's Healthcare of Atlanta (K.M.T.) - all in Atlanta; the Department of Pediatrics, University of Cincinnati College of Medicine, Cincinnati Children's Hospital Medical Center, Cincinnati (M.A.S.), the Division of Pediatric Critical Care Medicine, Nationwide Children's Hospital, Columbus (K.E.B.), and the Division of Critical Care Medicine, Department of Pediatrics, Akron Children's Hospital, Akron (R.A.N.) - all in Ohio; the Department of Anesthesiology, Critical Care, and Pain Medicine, Boston Children's Hospital (M.M.N., A.G.R.), and the Departments of Anaesthesia and Pediatrics, Harvard Medical School (A.G.R.) - both in Boston; the Division of Infectious Diseases, Children's Hospital Los Angeles, and the Departments of Pediatrics and Molecular Microbiology and Immunology, University of Southern California, Los Angeles, Los Angeles (P.S.P.), the Division of Pediatric Hospital Medicine, UC San Diego-Rady Children's Hospital, San Diego (M.A.C.), the Department of Pediatrics, Divisions of Critical Care Medicine and Allergy, Immunology, and Bone Marrow Transplant, University of California, San Francisco, San Francisco (M.S.Z.), and the Division of Critical Care Medicine, UCSF Benioff Children's Hospital, Oakland (N.Z.C.) - all in California; the Department of Pediatrics, Baylor College of Medicine, Immunization Project, Texas Children's Hospital, Houston (J.A.B., L.C.S.); the Division of Critical Care Medicine, Department of Anesthesiology and Critical Care, Children's Hospital of Philadelphia, Philadelphia (K.C.); the Department of Pediatrics, Division of Infectious Diseases, University of Mississippi Medical Center, Jackson (C.V.H.); the Department of Pediatrics, Section of Critical Care Medicine, University of Colorado School of Medicine, and Children's Hospital Colorado, Aurora (A.B.M.); the Division of Critical Care Medicine, Department of Pediatrics, Northwestern University Feinberg School of Medicine, Ann and Robert H. Lurie Children's Hospital of Chicago, Chicago (B.M.C., K.N.M.); the Division of Pediatric Critical Care Medicine, Children's Hospital of Michigan, Central Michigan University, Detroit (S.M.H.), and the Division of Pediatric Critical Care Medicine, Department of Pediatrics, Mott Children's Hospital and University of Michigan, Ann Arbor (H.R.F.); the Section of Pediatric Critical Care, Department of Pediatrics, Arkansas Children's Hospital, Little Rock (K.I.); the Division of Pediatric Critical Care Medicine (E.H.M.), and the Department of Pediatrics (L.S.), Medical University of South Carolina, Charleston; the Department of Pediatrics, University of North Carolina at Chapel Hill Children's Hospital, Chapel Hill (S.P.S., T.C.W.); the Division of Pediatric Critical Care, Department of Pediatrics, Cooperman Barnabas Medical Center, Livingston, NJ (S.J.G.); the Division of Pediatric Infectious Diseases, Department of Pediatrics, Children's Mercy Kansas City, Kansas City, Missouri (J.E.S.); the Ryan White Center for Pediatric Infectious Disease and Global Health, Department of Pediatrics, Indiana University School of Medicine, Indianapolis (S.S.B.); the Department of Pediatrics, Division of Critical Care Medicine, University of Texas Southwestern, Children's Medical Center, Dallas (M.M.); the Division of Pediatric Critical Care, University of Minnesota Masonic Children's Hospital, Minneapolis (J.R.H.), and the Divisions of Pediatric Infectious Diseases and Pediatric Critical Care Medicine, Department of Pediatric and Adolescent Medicine, Mayo Clinic, Rochester (E.R.L.) - both in Minnesota; the Division of Pediatric Critical Care, Department of Pediatrics, University of Utah, Salt Lake City (H.C.); the Department of Pediatrics, Division of Cardiology, Louisiana State University Health Sciences Center and Children's Hospital of New Orleans, New Orleans (T.T.B.); the Division of Pediatric Critical Care, Department of Pediatrics, Children's Hospital and Medical Center, Omaha, NE (M.L.C.); and the Division of Pediatric Critical Care Medicine, Department of Pediatrics, University of Alabama at Birmingham, Birmingham (M.K.).; Newhams MM; From the Division of Pediatric Infectious Diseases, Department of Pediatrics, Vanderbilt University Medical Center, Nashville (N.B.H.); the Covid-19 Response Team, Centers for Disease Control and Prevention (S.M.O., A.M.P., S.M.G., K.N.P., A.P.C., M.M.P.), the Center for Childhood Infections and Vaccines of Children's Healthcare of Atlanta and the Department of Pediatrics, Emory University School of Medicine (S.K.), and the Division of Critical Care Medicine, Department of Pediatrics, Emory University School of Medicine, Children's Healthcare of Atlanta (K.M.T.) - all in Atlanta; the Department of Pediatrics, University of Cincinnati College of Medicine, Cincinnati Children's Hospital Medical Center, Cincinnati (M.A.S.), the Division of Pediatric Critical Care Medicine, Nationwide Children's Hospital, Columbus (K.E.B.), and the Division of Critical Care Medicine, Department of Pediatrics, Akron Children's Hospital, Akron (R.A.N.) - all in Ohio; the Department of Anesthesiology, Critical Care, and Pain Medicine, Boston Children's Hospital (M.M.N., A.G.R.), and the Departments of Anaesthesia and Pediatrics, Harvard Medical School (A.G.R.) - both in Boston; the Division of Infectious Diseases, Children's Hospital Los Angeles, and the Departments of Pediatrics and Molecular Microbiology and Immunology, University of Southern California, Los Angeles, Los Angeles (P.S.P.), the Division of Pediatric Hospital Medicine, UC San Diego-Rady Children's Hospital, San Diego (M.A.C.), the Department of Pediatrics, Divisions of Critical Care Medicine and Allergy, Immunology, and Bone Marrow Transplant, University of California, San Francisco, San Francisco (M.S.Z.), and the Division of Critical Care Medicine, UCSF Benioff Children's Hospital, Oakland (N.Z.C.) - all in California; the Department of Pediatrics, Baylor College of Medicine, Immunization Project, Texas Children's Hospital, Houston (J.A.B., L.C.S.); the Division of Critical Care Medicine, Department of Anesthesiology and Critical Care, Children's Hospital of Philadelphia, Philadelphia (K.C.); the Department of Pediatrics, Division of Infectious Diseases, University of Mississippi Medical Center, Jackson (C.V.H.); the Department of Pediatrics, Section of Critical Care Medicine, University of Colorado School of Medicine, and Children's Hospital Colorado, Aurora (A.B.M.); the Division of Critical Care Medicine, Department of Pediatrics, Northwestern University Feinberg School of Medicine, Ann and Robert H. Lurie Children's Hospital of Chicago, Chicago (B.M.C., K.N.M.); the Division of Pediatric Critical Care Medicine, Children's Hospital of Michigan, Central Michigan University, Detroit (S.M.H.), and the Division of Pediatric Critical Care Medicine, Department of Pediatrics, Mott Children's Hospital and University of Michigan, Ann Arbor (H.R.F.); the Section of Pediatric Critical Care, Department of Pediatrics, Arkansas Children's Hospital, Little Rock (K.I.); the Division of Pediatric Critical Care Medicine (E.H.M.), and the Department of Pediatrics (L.S.), Medical University of South Carolina, Charleston; the Department of Pediatrics, University of North Carolina at Chapel Hill Children's Hospital, Chapel Hill (S.P.S., T.C.W.); the Division of Pediatric Critical Care, Department of Pediatrics, Cooperman Barnabas Medical Center, Livingston, NJ (S.J.G.); the Division of Pediatric Infectious Diseases, Department of Pediatrics, Children's Mercy Kansas City, Kansas City, Missouri (J.E.S.); the Ryan White Center for Pediatric Infectious Disease and Global Health, Department of Pediatrics, Indiana University School of Medicine, Indianapolis (S.S.B.); the Department of Pediatrics, Division of Critical Care Medicine, University of Texas Southwestern, Children's Medical Center, Dallas (M.M.); the Division of Pediatric Critical Care, University of Minnesota Masonic Children's Hospital, Minneapolis (J.R.H.), and the Divisions of Pediatric Infectious Diseases and Pediatric Critical Care Medicine, Department of Pediatric and Adolescent Medicine, Mayo Clinic, Rochester (E.R.L.) - both in Minnesota; the Division of Pediatric Critical Care, Department of Pediatrics, University of Utah, Salt Lake City (H.C.); the Department of Pediatrics, Division of Cardiology, Louisiana State University Health Sciences Center and Children's Hospital of New Orleans, New Orleans (T.T.B.); the Division of Pediatric Critical Care, Department of Pediatrics, Children's Hospital and Medical Center, Omaha, NE (M.L.C.); and the Division of Pediatric Critical Care Medicine, Department of Pediatrics, University of Alabama at Birmingham, Birmingham (M.K.).; Price AM; From the Division of Pediatric Infectious Diseases, Department of Pediatrics, Vanderbilt University Medical Center, Nashville (N.B.H.); the Covid-19 Response Team, Centers for Disease Control and Prevention (S.M.O., A.M.P., S.M.G., K.N.P., A.P.C., M.M.P.), the Center for Childhood Infections and Vaccines of Children's Healthcare of Atlanta and the Department of Pediatrics, Emory University School of Medicine (S.K.), and the Division of Critical Care Medicine, Department of Pediatrics, Emory University School of Medicine, Children's Healthcare of Atlanta (K.M.T.) - all in Atlanta; the Department of Pediatrics, University of Cincinnati College of Medicine, Cincinnati Children's Hospital Medical Center, Cincinnati (M.A.S.), the Division of Pediatric Critical Care Medicine, Nationwide Children's Hospital, Columbus (K.E.B.), and the Division of Critical Care Medicine, Department of Pediatrics, Akron Children's Hospital, Akron (R.A.N.) - all in Ohio; the Department of Anesthesiology, Critical Care, and Pain Medicine, Boston Children's Hospital (M.M.N., A.G.R.), and the Departments of Anaesthesia and Pediatrics, Harvard Medical School (A.G.R.) - both in Boston; the Division of Infectious Diseases, Children's Hospital Los Angeles, and the Departments of Pediatrics and Molecular Microbiology and Immunology, University of Southern California, Los Angeles, Los Angeles (P.S.P.), the Division of Pediatric Hospital Medicine, UC San Diego-Rady Children's Hospital, San Diego (M.A.C.), the Department of Pediatrics, Divisions of Critical Care Medicine and Allergy, Immunology, and Bone Marrow Transplant, University of California, San Francisco, San Francisco (M.S.Z.), and the Division of Critical Care Medicine, UCSF Benioff Children's Hospital, Oakland (N.Z.C.) - all in California; the Department of Pediatrics, Baylor College of Medicine, Immunization Project, Texas Children's Hospital, Houston (J.A.B., L.C.S.); the Division of Critical Care Medicine, Department of Anesthesiology and Critical Care, Children's Hospital of Philadelphia, Philadelphia (K.C.); the Department of Pediatrics, Division of Infectious Diseases, University of Mississippi Medical Center, Jackson (C.V.H.); the Department of Pediatrics, Section of Critical Care Medicine, University of Colorado School of Medicine, and Children's Hospital Colorado, Aurora (A.B.M.); the Division of Critical Care Medicine, Department of Pediatrics, Northwestern University Feinberg School of Medicine, Ann and Robert H. Lurie Children's Hospital of Chicago, Chicago (B.M.C., K.N.M.); the Division of Pediatric Critical Care Medicine, Children's Hospital of Michigan, Central Michigan University, Detroit (S.M.H.), and the Division of Pediatric Critical Care Medicine, Department of Pediatrics, Mott Children's Hospital and University of Michigan, Ann Arbor (H.R.F.); the Section of Pediatric Critical Care, Department of Pediatrics, Arkansas Children's Hospital, Little Rock (K.I.); the Division of Pediatric Critical Care Medicine (E.H.M.), and the Department of Pediatrics (L.S.), Medical University of South Carolina, Charleston; the Department of Pediatrics, University of North Carolina at Chapel Hill Children's Hospital, Chapel Hill (S.P.S., T.C.W.); the Division of Pediatric Critical Care, Department of Pediatrics, Cooperman Barnabas Medical Center, Livingston, NJ (S.J.G.); the Division of Pediatric Infectious Diseases, Department of Pediatrics, Children's Mercy Kansas City, Kansas City, Missouri (J.E.S.); the Ryan White Center for Pediatric Infectious Disease and Global Health, Department of Pediatrics, Indiana University School of Medicine, Indianapolis (S.S.B.); the Department of Pediatrics, Division of Critical Care Medicine, University of Texas Southwestern, Children's Medical Center, Dallas (M.M.); the Division of Pediatric Critical Care, University of Minnesota Masonic Children's Hospital, Minneapolis (J.R.H.), and the Divisions of Pediatric Infectious Diseases and Pediatric Critical Care Medicine, Department of Pediatric and Adolescent Medicine, Mayo Clinic, Rochester (E.R.L.) - both in Minnesota; the Division of Pediatric Critical Care, Department of Pediatrics, University of Utah, Salt Lake City (H.C.); the Department of Pediatrics, Division of Cardiology, Louisiana State University Health Sciences Center and Children's Hospital of New Orleans, New Orleans (T.T.B.); the Division of Pediatric Critical Care, Department of Pediatrics, Children's Hospital and Medical Center, Omaha, NE (M.L.C.); and the Division of Pediatric Critical Care Medicine, Department of Pediatrics, University of Alabama at Birmingham, Birmingham (M.K.).; Pannaraj PS; From the Division of Pediatric Infectious Diseases, Department of Pediatrics, Vanderbilt University Medical Center, Nashville (N.B.H.); the Covid-19 Response Team, Centers for Disease Control and Prevention (S.M.O., A.M.P., S.M.G., K.N.P., A.P.C., M.M.P.), the Center for Childhood Infections and Vaccines of Children's Healthcare of Atlanta and the Department of Pediatrics, Emory University School of Medicine (S.K.), and the Division of Critical Care Medicine, Department of Pediatrics, Emory University School of Medicine, Children's Healthcare of Atlanta (K.M.T.) - all in Atlanta; the Department of Pediatrics, University of Cincinnati College of Medicine, Cincinnati Children's Hospital Medical Center, Cincinnati (M.A.S.), the Division of Pediatric Critical Care Medicine, Nationwide Children's Hospital, Columbus (K.E.B.), and the Division of Critical Care Medicine, Department of Pediatrics, Akron Children's Hospital, Akron (R.A.N.) - all in Ohio; the Department of Anesthesiology, Critical Care, and Pain Medicine, Boston Children's Hospital (M.M.N., A.G.R.), and the Departments of Anaesthesia and Pediatrics, Harvard Medical School (A.G.R.) - both in Boston; the Division of Infectious Diseases, Children's Hospital Los Angeles, and the Departments of Pediatrics and Molecular Microbiology and Immunology, University of Southern California, Los Angeles, Los Angeles (P.S.P.), the Division of Pediatric Hospital Medicine, UC San Diego-Rady Children's Hospital, San Diego (M.A.C.), the Department of Pediatrics, Divisions of Critical Care Medicine and Allergy, Immunology, and Bone Marrow Transplant, University of California, San Francisco, San Francisco (M.S.Z.), and the Division of Critical Care Medicine, UCSF Benioff Children's Hospital, Oakland (N.Z.C.) - all in California; the Department of Pediatrics, Baylor College of Medicine, Immunization Project, Texas Children's Hospital, Houston (J.A.B., L.C.S.); the Division of Critical Care Medicine, Department of Anesthesiology and Critical Care, Children's Hospital of Philadelphia, Philadelphia (K.C.); the Department of Pediatrics, Division of Infectious Diseases, University of Mississippi Medical Center, Jackson (C.V.H.); the Department of Pediatrics, Section of Critical Care Medicine, University of Colorado School of Medicine, and Children's Hospital Colorado, Aurora (A.B.M.); the Division of Critical Care Medicine, Department of Pediatrics, Northwestern University Feinberg School of Medicine, Ann and Robert H. Lurie Children's Hospital of Chicago, Chicago (B.M.C., K.N.M.); the Division of Pediatric Critical Care Medicine, Children's Hospital of Michigan, Central Michigan University, Detroit (S.M.H.), and the Division of Pediatric Critical Care Medicine, Department of Pediatrics, Mott Children's Hospital and University of Michigan, Ann Arbor (H.R.F.); the Section of Pediatric Critical Care, Department of Pediatrics, Arkansas Children's Hospital, Little Rock (K.I.); the Division of Pediatric Critical Care Medicine (E.H.M.), and the Department of Pediatrics (L.S.), Medical University of South Carolina, Charleston; the Department of Pediatrics, University of North Carolina at Chapel Hill Children's Hospital, Chapel Hill (S.P.S., T.C.W.); the Division of Pediatric Critical Care, Department of Pediatrics, Cooperman Barnabas Medical Center, Livingston, NJ (S.J.G.); the Division of Pediatric Infectious Diseases, Department of Pediatrics, Children's Mercy Kansas City, Kansas City, Missouri (J.E.S.); the Ryan White Center for Pediatric Infectious Disease and Global Health, Department of Pediatrics, Indiana University School of Medicine, Indianapolis (S.S.B.); the Department of Pediatrics, Division of Critical Care Medicine, University of Texas Southwestern, Children's Medical Center, Dallas (M.M.); the Division of Pediatric Critical Care, University of Minnesota Masonic Children's Hospital, Minneapolis (J.R.H.), and the Divisions of Pediatric Infectious Diseases and Pediatric Critical Care Medicine, Department of Pediatric and Adolescent Medicine, Mayo Clinic, Rochester (E.R.L.) - both in Minnesota; the Division of Pediatric Critical Care, Department of Pediatrics, University of Utah, Salt Lake City (H.C.); the Department of Pediatrics, Division of Cardiology, Louisiana State University Health Sciences Center and Children's Hospital of New Orleans, New Orleans (T.T.B.); the Division of Pediatric Critical Care, Department of Pediatrics, Children's Hospital and Medical Center, Omaha, NE (M.L.C.); and the Division of Pediatric Critical Care Medicine, Department of Pediatrics, University of Alabama at Birmingham, Birmingham (M.K.).; Boom JA; From the Division of Pediatric Infectious Diseases, Department of Pediatrics, Vanderbilt University Medical Center, Nashville (N.B.H.); the Covid-19 Response Team, Centers for Disease Control and Prevention (S.M.O., A.M.P., S.M.G., K.N.P., A.P.C., M.M.P.), the Center for Childhood Infections and Vaccines of Children's Healthcare of Atlanta and the Department of Pediatrics, Emory University School of Medicine (S.K.), and the Division of Critical Care Medicine, Department of Pediatrics, Emory University School of Medicine, Children's Healthcare of Atlanta (K.M.T.) - all in Atlanta; the Department of Pediatrics, University of Cincinnati College of Medicine, Cincinnati Children's Hospital Medical Center, Cincinnati (M.A.S.), the Division of Pediatric Critical Care Medicine, Nationwide Children's Hospital, Columbus (K.E.B.), and the Division of Critical Care Medicine, Department of Pediatrics, Akron Children's Hospital, Akron (R.A.N.) - all in Ohio; the Department of Anesthesiology, Critical Care, and Pain Medicine, Boston Children's Hospital (M.M.N., A.G.R.), and the Departments of Anaesthesia and Pediatrics, Harvard Medical School (A.G.R.) - both in Boston; the Division of Infectious Diseases, Children's Hospital Los Angeles, and the Departments of Pediatrics and Molecular Microbiology and Immunology, University of Southern California, Los Angeles, Los Angeles (P.S.P.), the Division of Pediatric Hospital Medicine, UC San Diego-Rady Children's Hospital, San Diego (M.A.C.), the Department of Pediatrics, Divisions of Critical Care Medicine and Allergy, Immunology, and Bone Marrow Transplant, University of California, San Francisco, San Francisco (M.S.Z.), and the Division of Critical Care Medicine, UCSF Benioff Children's Hospital, Oakland (N.Z.C.) - all in California; the Department of Pediatrics, Baylor College of Medicine, Immunization Project, Texas Children's Hospital, Houston (J.A.B., L.C.S.); the Division of Critical Care Medicine, Department of Anesthesiology and Critical Care, Children's Hospital of Philadelphia, Philadelphia (K.C.); the Department of Pediatrics, Division of Infectious Diseases, University of Mississippi Medical Center, Jackson (C.V.H.); the Department of Pediatrics, Section of Critical Care Medicine, University of Colorado School of Medicine, and Children's Hospital Colorado, Aurora (A.B.M.); the Division of Critical Care Medicine, Department of Pediatrics, Northwestern University Feinberg School of Medicine, Ann and Robert H. Lurie Children's Hospital of Chicago, Chicago (B.M.C., K.N.M.); the Division of Pediatric Critical Care Medicine, Children's Hospital of Michigan, Central Michigan University, Detroit (S.M.H.), and the Division of Pediatric Critical Care Medicine, Department of Pediatrics, Mott Children's Hospital and University of Michigan, Ann Arbor (H.R.F.); the Section of Pediatric Critical Care, Department of Pediatrics, Arkansas Children's Hospital, Little Rock (K.I.); the Division of Pediatric Critical Care Medicine (E.H.M.), and the Department of Pediatrics (L.S.), Medical University of South Carolina, Charleston; the Department of Pediatrics, University of North Carolina at Chapel Hill Children's Hospital, Chapel Hill (S.P.S., T.C.W.); the Division of Pediatric Critical Care, Department of Pediatrics, Cooperman Barnabas Medical Center, Livingston, NJ (S.J.G.); the Division of Pediatric Infectious Diseases, Department of Pediatrics, Children's Mercy Kansas City, Kansas City, Missouri (J.E.S.); the Ryan White Center for Pediatric Infectious Disease and Global Health, Department of Pediatrics, Indiana University School of Medicine, Indianapolis (S.S.B.); the Department of Pediatrics, Division of Critical Care Medicine, University of Texas Southwestern, Children's Medical Center, Dallas (M.M.); the Division of Pediatric Critical Care, University of Minnesota Masonic Children's Hospital, Minneapolis (J.R.H.), and the Divisions of Pediatric Infectious Diseases and Pediatric Critical Care Medicine, Department of Pediatric and Adolescent Medicine, Mayo Clinic, Rochester (E.R.L.) - both in Minnesota; the Division of Pediatric Critical Care, Department of Pediatrics, University of Utah, Salt Lake City (H.C.); the Department of Pediatrics, Division of Cardiology, Louisiana State University Health Sciences Center and Children's Hospital of New Orleans, New Orleans (T.T.B.); the Division of Pediatric Critical Care, Department of Pediatrics, Children's Hospital and Medical Center, Omaha, NE (M.L.C.); and the Division of Pediatric Critical Care Medicine, Department of Pediatrics, University of Alabama at Birmingham, Birmingham (M.K.).; Sahni LC; From the Division of Pediatric Infectious Diseases, Department of Pediatrics, Vanderbilt University Medical Center, Nashville (N.B.H.); the Covid-19 Response Team, Centers for Disease Control and Prevention (S.M.O., A.M.P., S.M.G., K.N.P., A.P.C., M.M.P.), the Center for Childhood Infections and Vaccines of Children's Healthcare of Atlanta and the Department of Pediatrics, Emory University School of Medicine (S.K.), and the Division of Critical Care Medicine, Department of Pediatrics, Emory University School of Medicine, Children's Healthcare of Atlanta (K.M.T.) - all in Atlanta; the Department of Pediatrics, University of Cincinnati College of Medicine, Cincinnati Children's Hospital Medical Center, Cincinnati (M.A.S.), the Division of Pediatric Critical Care Medicine, Nationwide Children's Hospital, Columbus (K.E.B.), and the Division of Critical Care Medicine, Department of Pediatrics, Akron Children's Hospital, Akron (R.A.N.) - all in Ohio; the Department of Anesthesiology, Critical Care, and Pain Medicine, Boston Children's Hospital (M.M.N., A.G.R.), and the Departments of Anaesthesia and Pediatrics, Harvard Medical School (A.G.R.) - both in Boston; the Division of Infectious Diseases, Children's Hospital Los Angeles, and the Departments of Pediatrics and Molecular Microbiology and Immunology, University of Southern California, Los Angeles, Los Angeles (P.S.P.), the Division of Pediatric Hospital Medicine, UC San Diego-Rady Children's Hospital, San Diego (M.A.C.), the Department of Pediatrics, Divisions of Critical Care Medicine and Allergy, Immunology, and Bone Marrow Transplant, University of California, San Francisco, San Francisco (M.S.Z.), and the Division of Critical Care Medicine, UCSF Benioff Children's Hospital, Oakland (N.Z.C.) - all in California; the Department of Pediatrics, Baylor College of Medicine, Immunization Project, Texas Children's Hospital, Houston (J.A.B., L.C.S.); the Division of Critical Care Medicine, Department of Anesthesiology and Critical Care, Children's Hospital of Philadelphia, Philadelphia (K.C.); the Department of Pediatrics, Division of Infectious Diseases, University of Mississippi Medical Center, Jackson (C.V.H.); the Department of Pediatrics, Section of Critical Care Medicine, University of Colorado School of Medicine, and Children's Hospital Colorado, Aurora (A.B.M.); the Division of Critical Care Medicine, Department of Pediatrics, Northwestern University Feinberg School of Medicine, Ann and Robert H. Lurie Children's Hospital of Chicago, Chicago (B.M.C., K.N.M.); the Division of Pediatric Critical Care Medicine, Children's Hospital of Michigan, Central Michigan University, Detroit (S.M.H.), and the Division of Pediatric Critical Care Medicine, Department of Pediatrics, Mott Children's Hospital and University of Michigan, Ann Arbor (H.R.F.); the Section of Pediatric Critical Care, Department of Pediatrics, Arkansas Children's Hospital, Little Rock (K.I.); the Division of Pediatric Critical Care Medicine (E.H.M.), and the Department of Pediatrics (L.S.), Medical University of South Carolina, Charleston; the Department of Pediatrics, University of North Carolina at Chapel Hill Children's Hospital, Chapel Hill (S.P.S., T.C.W.); the Division of Pediatric Critical Care, Department of Pediatrics, Cooperman Barnabas Medical Center, Livingston, NJ (S.J.G.); the Division of Pediatric Infectious Diseases, Department of Pediatrics, Children's Mercy Kansas City, Kansas City, Missouri (J.E.S.); the Ryan White Center for Pediatric Infectious Disease and Global Health, Department of Pediatrics, Indiana University School of Medicine, Indianapolis (S.S.B.); the Department of Pediatrics, Division of Critical Care Medicine, University of Texas Southwestern, Children's Medical Center, Dallas (M.M.); the Division of Pediatric Critical Care, University of Minnesota Masonic Children's Hospital, Minneapolis (J.R.H.), and the Divisions of Pediatric Infectious Diseases and Pediatric Critical Care Medicine, Department of Pediatric and Adolescent Medicine, Mayo Clinic, Rochester (E.R.L.) - both in Minnesota; the Division of Pediatric Critical Care, Department of Pediatrics, University of Utah, Salt Lake City (H.C.); the Department of Pediatrics, Division of Cardiology, Louisiana State University Health Sciences Center and Children's Hospital of New Orleans, New Orleans (T.T.B.); the Division of Pediatric Critical Care, Department of Pediatrics, Children's Hospital and Medical Center, Omaha, NE (M.L.C.); and the Division of Pediatric Critical Care Medicine, Department of Pediatrics, University of Alabama at Birmingham, Birmingham (M.K.).; Chiotos K; From the Division of Pediatric Infectious Diseases, Department of Pediatrics, Vanderbilt University Medical Center, Nashville (N.B.H.); the Covid-19 Response Team, Centers for Disease Control and Prevention (S.M.O., A.M.P., S.M.G., K.N.P., A.P.C., M.M.P.), the Center for Childhood Infections and Vaccines of Children's Healthcare of Atlanta and the Department of Pediatrics, Emory University School of Medicine (S.K.), and the Division of Critical Care Medicine, Department of Pediatrics, Emory University School of Medicine, Children's Healthcare of Atlanta (K.M.T.) - all in Atlanta; the Department of Pediatrics, University of Cincinnati College of Medicine, Cincinnati Children's Hospital Medical Center, Cincinnati (M.A.S.), the Division of Pediatric Critical Care Medicine, Nationwide Children's Hospital, Columbus (K.E.B.), and the Division of Critical Care Medicine, Department of Pediatrics, Akron Children's Hospital, Akron (R.A.N.) - all in Ohio; the Department of Anesthesiology, Critical Care, and Pain Medicine, Boston Children's Hospital (M.M.N., A.G.R.), and the Departments of Anaesthesia and Pediatrics, Harvard Medical School (A.G.R.) - both in Boston; the Division of Infectious Diseases, Children's Hospital Los Angeles, and the Departments of Pediatrics and Molecular Microbiology and Immunology, University of Southern California, Los Angeles, Los Angeles (P.S.P.), the Division of Pediatric Hospital Medicine, UC San Diego-Rady Children's Hospital, San Diego (M.A.C.), the Department of Pediatrics, Divisions of Critical Care Medicine and Allergy, Immunology, and Bone Marrow Transplant, University of California, San Francisco, San Francisco (M.S.Z.), and the Division of Critical Care Medicine, UCSF Benioff Children's Hospital, Oakland (N.Z.C.) - all in California; the Department of Pediatrics, Baylor College of Medicine, Immunization Project, Texas Children's Hospital, Houston (J.A.B., L.C.S.); the Division of Critical Care Medicine, Department of Anesthesiology and Critical Care, Children's Hospital of Philadelphia, Philadelphia (K.C.); the Department of Pediatrics, Division of Infectious Diseases, University of Mississippi Medical Center, Jackson (C.V.H.); the Department of Pediatrics, Section of Critical Care Medicine, University of Colorado School of Medicine, and Children's Hospital Colorado, Aurora (A.B.M.); the Division of Critical Care Medicine, Department of Pediatrics, Northwestern University Feinberg School of Medicine, Ann and Robert H. Lurie Children's Hospital of Chicago, Chicago (B.M.C., K.N.M.); the Division of Pediatric Critical Care Medicine, Children's Hospital of Michigan, Central Michigan University, Detroit (S.M.H.), and the Division of Pediatric Critical Care Medicine, Department of Pediatrics, Mott Children's Hospital and University of Michigan, Ann Arbor (H.R.F.); the Section of Pediatric Critical Care, Department of Pediatrics, Arkansas Children's Hospital, Little Rock (K.I.); the Division of Pediatric Critical Care Medicine (E.H.M.), and the Department of Pediatrics (L.S.), Medical University of South Carolina, Charleston; the Department of Pediatrics, University of North Carolina at Chapel Hill Children's Hospital, Chapel Hill (S.P.S., T.C.W.); the Division of Pediatric Critical Care, Department of Pediatrics, Cooperman Barnabas Medical Center, Livingston, NJ (S.J.G.); the Division of Pediatric Infectious Diseases, Department of Pediatrics, Children's Mercy Kansas City, Kansas City, Missouri (J.E.S.); the Ryan White Center for Pediatric Infectious Disease and Global Health, Department of Pediatrics, Indiana University School of Medicine, Indianapolis (S.S.B.); the Department of Pediatrics, Division of Critical Care Medicine, University of Texas Southwestern, Children's Medical Center, Dallas (M.M.); the Division of Pediatric Critical Care, University of Minnesota Masonic Children's Hospital, Minneapolis (J.R.H.), and the Divisions of Pediatric Infectious Diseases and Pediatric Critical Care Medicine, Department of Pediatric and Adolescent Medicine, Mayo Clinic, Rochester (E.R.L.) - both in Minnesota; the Division of Pediatric Critical Care, Department of Pediatrics, University of Utah, Salt Lake City (H.C.); the Department of Pediatrics, Division of Cardiology, Louisiana State University Health Sciences Center and Children's Hospital of New Orleans, New Orleans (T.T.B.); the Division of Pediatric Critical Care, Department of Pediatrics, Children's Hospital and Medical Center, Omaha, NE (M.L.C.); and the Division of Pediatric Critical Care Medicine, Department of Pediatrics, University of Alabama at Birmingham, Birmingham (M.K.).; Cameron MA; From the Division of Pediatric Infectious Diseases, Department of Pediatrics, Vanderbilt University Medical Center, Nashville (N.B.H.); the Covid-19 Response Team, Centers for Disease Control and Prevention (S.M.O., A.M.P., S.M.G., K.N.P., A.P.C., M.M.P.), the Center for Childhood Infections and Vaccines of Children's Healthcare of Atlanta and the Department of Pediatrics, Emory University School of Medicine (S.K.), and the Division of Critical Care Medicine, Department of Pediatrics, Emory University School of Medicine, Children's Healthcare of Atlanta (K.M.T.) - all in Atlanta; the Department of Pediatrics, University of Cincinnati College of Medicine, Cincinnati Children's Hospital Medical Center, Cincinnati (M.A.S.), the Division of Pediatric Critical Care Medicine, Nationwide Children's Hospital, Columbus (K.E.B.), and the Division of Critical Care Medicine, Department of Pediatrics, Akron Children's Hospital, Akron (R.A.N.) - all in Ohio; the Department of Anesthesiology, Critical Care, and Pain Medicine, Boston Children's Hospital (M.M.N., A.G.R.), and the Departments of Anaesthesia and Pediatrics, Harvard Medical School (A.G.R.) - both in Boston; the Division of Infectious Diseases, Children's Hospital Los Angeles, and the Departments of Pediatrics and Molecular Microbiology and Immunology, University of Southern California, Los Angeles, Los Angeles (P.S.P.), the Division of Pediatric Hospital Medicine, UC San Diego-Rady Children's Hospital, San Diego (M.A.C.), the Department of Pediatrics, Divisions of Critical Care Medicine and Allergy, Immunology, and Bone Marrow Transplant, University of California, San Francisco, San Francisco (M.S.Z.), and the Division of Critical Care Medicine, UCSF Benioff Children's Hospital, Oakland (N.Z.C.) - all in California; the Department of Pediatrics, Baylor College of Medicine, Immunization Project, Texas Children's Hospital, Houston (J.A.B., L.C.S.); the Division of Critical Care Medicine, Department of Anesthesiology and Critical Care, Children's Hospital of Philadelphia, Philadelphia (K.C.); the Department of Pediatrics, Division of Infectious Diseases, University of Mississippi Medical Center, Jackson (C.V.H.); the Department of Pediatrics, Section of Critical Care Medicine, University of Colorado School of Medicine, and Children's Hospital Colorado, Aurora (A.B.M.); the Division of Critical Care Medicine, Department of Pediatrics, Northwestern University Feinberg School of Medicine, Ann and Robert H. Lurie Children's Hospital of Chicago, Chicago (B.M.C., K.N.M.); the Division of Pediatric Critical Care Medicine, Children's Hospital of Michigan, Central Michigan University, Detroit (S.M.H.), and the Division of Pediatric Critical Care Medicine, Department of Pediatrics, Mott Children's Hospital and University of Michigan, Ann Arbor (H.R.F.); the Section of Pediatric Critical Care, Department of Pediatrics, Arkansas Children's Hospital, Little Rock (K.I.); the Division of Pediatric Critical Care Medicine (E.H.M.), and the Department of Pediatrics (L.S.), Medical University of South Carolina, Charleston; the Department of Pediatrics, University of North Carolina at Chapel Hill Children's Hospital, Chapel Hill (S.P.S., T.C.W.); the Division of Pediatric Critical Care, Department of Pediatrics, Cooperman Barnabas Medical Center, Livingston, NJ (S.J.G.); the Division of Pediatric Infectious Diseases, Department of Pediatrics, Children's Mercy Kansas City, Kansas City, Missouri (J.E.S.); the Ryan White Center for Pediatric Infectious Disease and Global Health, Department of Pediatrics, Indiana University School of Medicine, Indianapolis (S.S.B.); the Department of Pediatrics, Division of Critical Care Medicine, University of Texas Southwestern, Children's Medical Center, Dallas (M.M.); the Division of Pediatric Critical Care, University of Minnesota Masonic Children's Hospital, Minneapolis (J.R.H.), and the Divisions of Pediatric Infectious Diseases and Pediatric Critical Care Medicine, Department of Pediatric and Adolescent Medicine, Mayo Clinic, Rochester (E.R.L.) - both in Minnesota; the Division of Pediatric Critical Care, Department of Pediatrics, University of Utah, Salt Lake City (H.C.); the Department of Pediatrics, Division of Cardiology, Louisiana State University Health Sciences Center and Children's Hospital of New Orleans, New Orleans (T.T.B.); the Division of Pediatric Critical Care, Department of Pediatrics, Children's Hospital and Medical Center, Omaha, NE (M.L.C.); and the Division of Pediatric Critical Care Medicine, Department of Pediatrics, University of Alabama at Birmingham, Birmingham (M.K.).; Bline KE; From the Division of Pediatric Infectious Diseases, Department of Pediatrics, Vanderbilt University Medical Center, Nashville (N.B.H.); the Covid-19 Response Team, Centers for Disease Control and Prevention (S.M.O., A.M.P., S.M.G., K.N.P., A.P.C., M.M.P.), the Center for Childhood Infections and Vaccines of Children's Healthcare of Atlanta and the Department of Pediatrics, Emory University School of Medicine (S.K.), and the Division of Critical Care Medicine, Department of Pediatrics, Emory University School of Medicine, Children's Healthcare of Atlanta (K.M.T.) - all in Atlanta; the Department of Pediatrics, University of Cincinnati College of Medicine, Cincinnati Children's Hospital Medical Center, Cincinnati (M.A.S.), the Division of Pediatric Critical Care Medicine, Nationwide Children's Hospital, Columbus (K.E.B.), and the Division of Critical Care Medicine, Department of Pediatrics, Akron Children's Hospital, Akron (R.A.N.) - all in Ohio; the Department of Anesthesiology, Critical Care, and Pain Medicine, Boston Children's Hospital (M.M.N., A.G.R.), and the Departments of Anaesthesia and Pediatrics, Harvard Medical School (A.G.R.) - both in Boston; the Division of Infectious Diseases, Children's Hospital Los Angeles, and the Departments of Pediatrics and Molecular Microbiology and Immunology, University of Southern California, Los Angeles, Los Angeles (P.S.P.), the Division of Pediatric Hospital Medicine, UC San Diego-Rady Children's Hospital, San Diego (M.A.C.), the Department of Pediatrics, Divisions of Critical Care Medicine and Allergy, Immunology, and Bone Marrow Transplant, University of California, San Francisco, San Francisco (M.S.Z.), and the Division of Critical Care Medicine, UCSF Benioff Children's Hospital, Oakland (N.Z.C.) - all in California; the Department of Pediatrics, Baylor College of Medicine, Immunization Project, Texas Children's Hospital, Houston (J.A.B., L.C.S.); the Division of Critical Care Medicine, Department of Anesthesiology and Critical Care, Children's Hospital of Philadelphia, Philadelphia (K.C.); the Department of Pediatrics, Division of Infectious Diseases, University of Mississippi Medical Center, Jackson (C.V.H.); the Department of Pediatrics, Section of Critical Care Medicine, University of Colorado School of Medicine, and Children's Hospital Colorado, Aurora (A.B.M.); the Division of Critical Care Medicine, Department of Pediatrics, Northwestern University Feinberg School of Medicine, Ann and Robert H. Lurie Children's Hospital of Chicago, Chicago (B.M.C., K.N.M.); the Division of Pediatric Critical Care Medicine, Children's Hospital of Michigan, Central Michigan University, Detroit (S.M.H.), and the Division of Pediatric Critical Care Medicine, Department of Pediatrics, Mott Children's Hospital and University of Michigan, Ann Arbor (H.R.F.); the Section of Pediatric Critical Care, Department of Pediatrics, Arkansas Children's Hospital, Little Rock (K.I.); the Division of Pediatric Critical Care Medicine (E.H.M.), and the Department of Pediatrics (L.S.), Medical University of South Carolina, Charleston; the Department of Pediatrics, University of North Carolina at Chapel Hill Children's Hospital, Chapel Hill (S.P.S., T.C.W.); the Division of Pediatric Critical Care, Department of Pediatrics, Cooperman Barnabas Medical Center, Livingston, NJ (S.J.G.); the Division of Pediatric Infectious Diseases, Department of Pediatrics, Children's Mercy Kansas City, Kansas City, Missouri (J.E.S.); the Ryan White Center for Pediatric Infectious Disease and Global Health, Department of Pediatrics, Indiana University School of Medicine, Indianapolis (S.S.B.); the Department of Pediatrics, Division of Critical Care Medicine, University of Texas Southwestern, Children's Medical Center, Dallas (M.M.); the Division of Pediatric Critical Care, University of Minnesota Masonic Children's Hospital, Minneapolis (J.R.H.), and the Divisions of Pediatric Infectious Diseases and Pediatric Critical Care Medicine, Department of Pediatric and Adolescent Medicine, Mayo Clinic, Rochester (E.R.L.) - both in Minnesota; the Division of Pediatric Critical Care, Department of Pediatrics, University of Utah, Salt Lake City (H.C.); the Department of Pediatrics, Division of Cardiology, Louisiana State University Health Sciences Center and Children's Hospital of New Orleans, New Orleans (T.T.B.); the Division of Pediatric Critical Care, Department of Pediatrics, Children's Hospital and Medical Center, Omaha, NE (M.L.C.); and the Division of Pediatric Critical Care Medicine, Department of Pediatrics, University of Alabama at Birmingham, Birmingham (M.K.).; Hobbs CV; From the Division of Pediatric Infectious Diseases, Department of Pediatrics, Vanderbilt University Medical Center, Nashville (N.B.H.); the Covid-19 Response Team, Centers for Disease Control and Prevention (S.M.O., A.M.P., S.M.G., K.N.P., A.P.C., M.M.P.), the Center for Childhood Infections and Vaccines of Children's Healthcare of Atlanta and the Department of Pediatrics, Emory University School of Medicine (S.K.), and the Division of Critical Care Medicine, Department of Pediatrics, Emory University School of Medicine, Children's Healthcare of Atlanta (K.M.T.) - all in Atlanta; the Department of Pediatrics, University of Cincinnati College of Medicine, Cincinnati Children's Hospital Medical Center, Cincinnati (M.A.S.), the Division of Pediatric Critical Care Medicine, Nationwide Children's Hospital, Columbus (K.E.B.), and the Division of Critical Care Medicine, Department of Pediatrics, Akron Children's Hospital, Akron (R.A.N.) - all in Ohio; the Department of Anesthesiology, Critical Care, and Pain Medicine, Boston Children's Hospital (M.M.N., A.G.R.), and the Departments of Anaesthesia and Pediatrics, Harvard Medical School (A.G.R.) - both in Boston; the Division of Infectious Diseases, Children's Hospital Los Angeles, and the Departments of Pediatrics and Molecular Microbiology and Immunology, University of Southern California, Los Angeles, Los Angeles (P.S.P.), the Division of Pediatric Hospital Medicine, UC San Diego-Rady Children's Hospital, San Diego (M.A.C.), the Department of Pediatrics, Divisions of Critical Care Medicine and Allergy, Immunology, and Bone Marrow Transplant, University of California, San Francisco, San Francisco (M.S.Z.), and the Division of Critical Care Medicine, UCSF Benioff Children's Hospital, Oakland (N.Z.C.) - all in California; the Department of Pediatrics, Baylor College of Medicine, Immunization Project, Texas Children's Hospital, Houston (J.A.B., L.C.S.); the Division of Critical Care Medicine, Department of Anesthesiology and Critical Care, Children's Hospital of Philadelphia, Philadelphia (K.C.); the Department of Pediatrics, Division of Infectious Diseases, University of Mississippi Medical Center, Jackson (C.V.H.); the Department of Pediatrics, Section of Critical Care Medicine, University of Colorado School of Medicine, and Children's Hospital Colorado, Aurora (A.B.M.); the Division of Critical Care Medicine, Department of Pediatrics, Northwestern University Feinberg School of Medicine, Ann and Robert H. Lurie Children's Hospital of Chicago, Chicago (B.M.C., K.N.M.); the Division of Pediatric Critical Care Medicine, Children's Hospital of Michigan, Central Michigan University, Detroit (S.M.H.), and the Division of Pediatric Critical Care Medicine, Department of Pediatrics, Mott Children's Hospital and University of Michigan, Ann Arbor (H.R.F.); the Section of Pediatric Critical Care, Department of Pediatrics, Arkansas Children's Hospital, Little Rock (K.I.); the Division of Pediatric Critical Care Medicine (E.H.M.), and the Department of Pediatrics (L.S.), Medical University of South Carolina, Charleston; the Department of Pediatrics, University of North Carolina at Chapel Hill Children's Hospital, Chapel Hill (S.P.S., T.C.W.); the Division of Pediatric Critical Care, Department of Pediatrics, Cooperman Barnabas Medical Center, Livingston, NJ (S.J.G.); the Division of Pediatric Infectious Diseases, Department of Pediatrics, Children's Mercy Kansas City, Kansas City, Missouri (J.E.S.); the Ryan White Center for Pediatric Infectious Disease and Global Health, Department of Pediatrics, Indiana University School of Medicine, Indianapolis (S.S.B.); the Department of Pediatrics, Division of Critical Care Medicine, University of Texas Southwestern, Children's Medical Center, Dallas (M.M.); the Division of Pediatric Critical Care, University of Minnesota Masonic Children's Hospital, Minneapolis (J.R.H.), and the Divisions of Pediatric Infectious Diseases and Pediatric Critical Care Medicine, Department of Pediatric and Adolescent Medicine, Mayo Clinic, Rochester (E.R.L.) - both in Minnesota; the Division of Pediatric Critical Care, Department of Pediatrics, University of Utah, Salt Lake City (H.C.); the Department of Pediatrics, Division of Cardiology, Louisiana State University Health Sciences Center and Children's Hospital of New Orleans, New Orleans (T.T.B.); the Division of Pediatric Critical Care, Department of Pediatrics, Children's Hospital and Medical Center, Omaha, NE (M.L.C.); and the Division of Pediatric Critical Care Medicine, Department of Pediatrics, University of Alabama at Birmingham, Birmingham (M.K.).; Maddux AB; From the Division of Pediatric Infectious Diseases, Department of Pediatrics, Vanderbilt University Medical Center, Nashville (N.B.H.); the Covid-19 Response Team, Centers for Disease Control and Prevention (S.M.O., A.M.P., S.M.G., K.N.P., A.P.C., M.M.P.), the Center for Childhood Infections and Vaccines of Children's Healthcare of Atlanta and the Department of Pediatrics, Emory University School of Medicine (S.K.), and the Division of Critical Care Medicine, Department of Pediatrics, Emory University School of Medicine, Children's Healthcare of Atlanta (K.M.T.) - all in Atlanta; the Department of Pediatrics, University of Cincinnati College of Medicine, Cincinnati Children's Hospital Medical Center, Cincinnati (M.A.S.), the Division of Pediatric Critical Care Medicine, Nationwide Children's Hospital, Columbus (K.E.B.), and the Division of Critical Care Medicine, Department of Pediatrics, Akron Children's Hospital, Akron (R.A.N.) - all in Ohio; the Department of Anesthesiology, Critical Care, and Pain Medicine, Boston Children's Hospital (M.M.N., A.G.R.), and the Departments of Anaesthesia and Pediatrics, Harvard Medical School (A.G.R.) - both in Boston; the Division of Infectious Diseases, Children's Hospital Los Angeles, and the Departments of Pediatrics and Molecular Microbiology and Immunology, University of Southern California, Los Angeles, Los Angeles (P.S.P.), the Division of Pediatric Hospital Medicine, UC San Diego-Rady Children's Hospital, San Diego (M.A.C.), the Department of Pediatrics, Divisions of Critical Care Medicine and Allergy, Immunology, and Bone Marrow Transplant, University of California, San Francisco, San Francisco (M.S.Z.), and the Division of Critical Care Medicine, UCSF Benioff Children's Hospital, Oakland (N.Z.C.) - all in California; the Department of Pediatrics, Baylor College of Medicine, Immunization Project, Texas Children's Hospital, Houston (J.A.B., L.C.S.); the Division of Critical Care Medicine, Department of Anesthesiology and Critical Care, Children's Hospital of Philadelphia, Philadelphia (K.C.); the Department of Pediatrics, Division of Infectious Diseases, University of Mississippi Medical Center, Jackson (C.V.H.); the Department of Pediatrics, Section of Critical Care Medicine, University of Colorado School of Medicine, and Children's Hospital Colorado, Aurora (A.B.M.); the Division of Critical Care Medicine, Department of Pediatrics, Northwestern University Feinberg School of Medicine, Ann and Robert H. Lurie Children's Hospital of Chicago, Chicago (B.M.C., K.N.M.); the Division of Pediatric Critical Care Medicine, Children's Hospital of Michigan, Central Michigan University, Detroit (S.M.H.), and the Division of Pediatric Critical Care Medicine, Department of Pediatrics, Mott Children's Hospital and University of Michigan, Ann Arbor (H.R.F.); the Section of Pediatric Critical Care, Department of Pediatrics, Arkansas Children's Hospital, Little Rock (K.I.); the Division of Pediatric Critical Care Medicine (E.H.M.), and the Department of Pediatrics (L.S.), Medical University of South Carolina, Charleston; the Department of Pediatrics, University of North Carolina at Chapel Hill Children's Hospital, Chapel Hill (S.P.S., T.C.W.); the Division of Pediatric Critical Care, Department of Pediatrics, Cooperman Barnabas Medical Center, Livingston, NJ (S.J.G.); the Division of Pediatric Infectious Diseases, Department of Pediatrics, Children's Mercy Kansas City, Kansas City, Missouri (J.E.S.); the Ryan White Center for Pediatric Infectious Disease and Global Health, Department of Pediatrics, Indiana University School of Medicine, Indianapolis (S.S.B.); the Department of Pediatrics, Division of Critical Care Medicine, University of Texas Southwestern, Children's Medical Center, Dallas (M.M.); the Division of Pediatric Critical Care, University of Minnesota Masonic Children's Hospital, Minneapolis (J.R.H.), and the Divisions of Pediatric Infectious Diseases and Pediatric Critical Care Medicine, Department of Pediatric and Adolescent Medicine, Mayo Clinic, Rochester (E.R.L.) - both in Minnesota; the Division of Pediatric Critical Care, Department of Pediatrics, University of Utah, Salt Lake City (H.C.); the Department of Pediatrics, Division of Cardiology, Louisiana State University Health Sciences Center and Children's Hospital of New Orleans, New Orleans (T.T.B.); the Division of Pediatric Critical Care, Department of Pediatrics, Children's Hospital and Medical Center, Omaha, NE (M.L.C.); and the Division of Pediatric Critical Care Medicine, Department of Pediatrics, University of Alabama at Birmingham, Birmingham (M.K.).; Coates BM; From the Division of Pediatric Infectious Diseases, Department of Pediatrics, Vanderbilt University Medical Center, Nashville (N.B.H.); the Covid-19 Response Team, Centers for Disease Control and Prevention (S.M.O., A.M.P., S.M.G., K.N.P., A.P.C., M.M.P.), the Center for Childhood Infections and Vaccines of Children's Healthcare of Atlanta and the Department of Pediatrics, Emory University School of Medicine (S.K.), and the Division of Critical Care Medicine, Department of Pediatrics, Emory University School of Medicine, Children's Healthcare of Atlanta (K.M.T.) - all in Atlanta; the Department of Pediatrics, University of Cincinnati College of Medicine, Cincinnati Children's Hospital Medical Center, Cincinnati (M.A.S.), the Division of Pediatric Critical Care Medicine, Nationwide Children's Hospital, Columbus (K.E.B.), and the Division of Critical Care Medicine, Department of Pediatrics, Akron Children's Hospital, Akron (R.A.N.) - all in Ohio; the Department of Anesthesiology, Critical Care, and Pain Medicine, Boston Children's Hospital (M.M.N., A.G.R.), and the Departments of Anaesthesia and Pediatrics, Harvard Medical School (A.G.R.) - both in Boston; the Division of Infectious Diseases, Children's Hospital Los Angeles, and the Departments of Pediatrics and Molecular Microbiology and Immunology, University of Southern California, Los Angeles, Los Angeles (P.S.P.), the Division of Pediatric Hospital Medicine, UC San Diego-Rady Children's Hospital, San Diego (M.A.C.), the Department of Pediatrics, Divisions of Critical Care Medicine and Allergy, Immunology, and Bone Marrow Transplant, University of California, San Francisco, San Francisco (M.S.Z.), and the Division of Critical Care Medicine, UCSF Benioff Children's Hospital, Oakland (N.Z.C.) - all in California; the Department of Pediatrics, Baylor College of Medicine, Immunization Project, Texas Children's Hospital, Houston (J.A.B., L.C.S.); the Division of Critical Care Medicine, Department of Anesthesiology and Critical Care, Children's Hospital of Philadelphia, Philadelphia (K.C.); the Department of Pediatrics, Division of Infectious Diseases, University of Mississippi Medical Center, Jackson (C.V.H.); the Department of Pediatrics, Section of Critical Care Medicine, University of Colorado School of Medicine, and Children's Hospital Colorado, Aurora (A.B.M.); the Division of Critical Care Medicine, Department of Pediatrics, Northwestern University Feinberg School of Medicine, Ann and Robert H. Lurie Children's Hospital of Chicago, Chicago (B.M.C., K.N.M.); the Division of Pediatric Critical Care Medicine, Children's Hospital of Michigan, Central Michigan University, Detroit (S.M.H.), and the Division of Pediatric Critical Care Medicine, Department of Pediatrics, Mott Children's Hospital and University of Michigan, Ann Arbor (H.R.F.); the Section of Pediatric Critical Care, Department of Pediatrics, Arkansas Children's Hospital, Little Rock (K.I.); the Division of Pediatric Critical Care Medicine (E.H.M.), and the Department of Pediatrics (L.S.), Medical University of South Carolina, Charleston; the Department of Pediatrics, University of North Carolina at Chapel Hill Children's Hospital, Chapel Hill (S.P.S., T.C.W.); the Division of Pediatric Critical Care, Department of Pediatrics, Cooperman Barnabas Medical Center, Livingston, NJ (S.J.G.); the Division of Pediatric Infectious Diseases, Department of Pediatrics, Children's Mercy Kansas City, Kansas City, Missouri (J.E.S.); the Ryan White Center for Pediatric Infectious Disease and Global Health, Department of Pediatrics, Indiana University School of Medicine, Indianapolis (S.S.B.); the Department of Pediatrics, Division of Critical Care Medicine, University of Texas Southwestern, Children's Medical Center, Dallas (M.M.); the Division of Pediatric Critical Care, University of Minnesota Masonic Children's Hospital, Minneapolis (J.R.H.), and the Divisions of Pediatric Infectious Diseases and Pediatric Critical Care Medicine, Department of Pediatric and Adolescent Medicine, Mayo Clinic, Rochester (E.R.L.) - both in Minnesota; the Division of Pediatric Critical Care, Department of Pediatrics, University of Utah, Salt Lake City (H.C.); the Department of Pediatrics, Division of Cardiology, Louisiana State University Health Sciences Center and Children's Hospital of New Orleans, New Orleans (T.T.B.); the Division of Pediatric Critical Care, Department of Pediatrics, Children's Hospital and Medical Center, Omaha, NE (M.L.C.); and the Division of Pediatric Critical Care Medicine, Department of Pediatrics, University of Alabama at Birmingham, Birmingham (M.K.).; Michelson KN; From the Division of Pediatric Infectious Diseases, Department of Pediatrics, Vanderbilt University Medical Center, Nashville (N.B.H.); the Covid-19 Response Team, Centers for Disease Control and Prevention (S.M.O., A.M.P., S.M.G., K.N.P., A.P.C., M.M.P.), the Center for Childhood Infections and Vaccines of Children's Healthcare of Atlanta and the Department of Pediatrics, Emory University School of Medicine (S.K.), and the Division of Critical Care Medicine, Department of Pediatrics, Emory University School of Medicine, Children's Healthcare of Atlanta (K.M.T.) - all in Atlanta; the Department of Pediatrics, University of Cincinnati College of Medicine, Cincinnati Children's Hospital Medical Center, Cincinnati (M.A.S.), the Division of Pediatric Critical Care Medicine, Nationwide Children's Hospital, Columbus (K.E.B.), and the Division of Critical Care Medicine, Department of Pediatrics, Akron Children's Hospital, Akron (R.A.N.) - all in Ohio; the Department of Anesthesiology, Critical Care, and Pain Medicine, Boston Children's Hospital (M.M.N., A.G.R.), and the Departments of Anaesthesia and Pediatrics, Harvard Medical School (A.G.R.) - both in Boston; the Division of Infectious Diseases, Children's Hospital Los Angeles, and the Departments of Pediatrics and Molecular Microbiology and Immunology, University of Southern California, Los Angeles, Los Angeles (P.S.P.), the Division of Pediatric Hospital Medicine, UC San Diego-Rady Children's Hospital, San Diego (M.A.C.), the Department of Pediatrics, Divisions of Critical Care Medicine and Allergy, Immunology, and Bone Marrow Transplant, University of California, San Francisco, San Francisco (M.S.Z.), and the Division of Critical Care Medicine, UCSF Benioff Children's Hospital, Oakland (N.Z.C.) - all in California; the Department of Pediatrics, Baylor College of Medicine, Immunization Project, Texas Children's Hospital, Houston (J.A.B., L.C.S.); the Division of Critical Care Medicine, Department of Anesthesiology and Critical Care, Children's Hospital of Philadelphia, Philadelphia (K.C.); the Department of Pediatrics, Division of Infectious Diseases, University of Mississippi Medical Center, Jackson (C.V.H.); the Department of Pediatrics, Section of Critical Care Medicine, University of Colorado School of Medicine, and Children's Hospital Colorado, Aurora (A.B.M.); the Division of Critical Care Medicine, Department of Pediatrics, Northwestern University Feinberg School of Medicine, Ann and Robert H. Lurie Children's Hospital of Chicago, Chicago (B.M.C., K.N.M.); the Division of Pediatric Critical Care Medicine, Children's Hospital of Michigan, Central Michigan University, Detroit (S.M.H.), and the Division of Pediatric Critical Care Medicine, Department of Pediatrics, Mott Children's Hospital and University of Michigan, Ann Arbor (H.R.F.); the Section of Pediatric Critical Care, Department of Pediatrics, Arkansas Children's Hospital, Little Rock (K.I.); the Division of Pediatric Critical Care Medicine (E.H.M.), and the Department of Pediatrics (L.S.), Medical University of South Carolina, Charleston; the Department of Pediatrics, University of North Carolina at Chapel Hill Children's Hospital, Chapel Hill (S.P.S., T.C.W.); the Division of Pediatric Critical Care, Department of Pediatrics, Cooperman Barnabas Medical Center, Livingston, NJ (S.J.G.); the Division of Pediatric Infectious Diseases, Department of Pediatrics, Children's Mercy Kansas City, Kansas City, Missouri (J.E.S.); the Ryan White Center for Pediatric Infectious Disease and Global Health, Department of Pediatrics, Indiana University School of Medicine, Indianapolis (S.S.B.); the Department of Pediatrics, Division of Critical Care Medicine, University of Texas Southwestern, Children's Medical Center, Dallas (M.M.); the Division of Pediatric Critical Care, University of Minnesota Masonic Children's Hospital, Minneapolis (J.R.H.), and the Divisions of Pediatric Infectious Diseases and Pediatric Critical Care Medicine, Department of Pediatric and Adolescent Medicine, Mayo Clinic, Rochester (E.R.L.) - both in Minnesota; the Division of Pediatric Critical Care, Department of Pediatrics, University of Utah, Salt Lake City (H.C.); the Department of Pediatrics, Division of Cardiology, Louisiana State University Health Sciences Center and Children's Hospital of New Orleans, New Orleans (T.T.B.); the Division of Pediatric Critical Care, Department of Pediatrics, Children's Hospital and Medical Center, Omaha, NE (M.L.C.); and the Division of Pediatric Critical Care Medicine, Department of Pediatrics, University of Alabama at Birmingham, Birmingham (M.K.).; Heidemann SM; From the Division of Pediatric Infectious Diseases, Department of Pediatrics, Vanderbilt University Medical Center, Nashville (N.B.H.); the Covid-19 Response Team, Centers for Disease Control and Prevention (S.M.O., A.M.P., S.M.G., K.N.P., A.P.C., M.M.P.), the Center for Childhood Infections and Vaccines of Children's Healthcare of Atlanta and the Department of Pediatrics, Emory University School of Medicine (S.K.), and the Division of Critical Care Medicine, Department of Pediatrics, Emory University School of Medicine, Children's Healthcare of Atlanta (K.M.T.) - all in Atlanta; the Department of Pediatrics, University of Cincinnati College of Medicine, Cincinnati Children's Hospital Medical Center, Cincinnati (M.A.S.), the Division of Pediatric Critical Care Medicine, Nationwide Children's Hospital, Columbus (K.E.B.), and the Division of Critical Care Medicine, Department of Pediatrics, Akron Children's Hospital, Akron (R.A.N.) - all in Ohio; the Department of Anesthesiology, Critical Care, and Pain Medicine, Boston Children's Hospital (M.M.N., A.G.R.), and the Departments of Anaesthesia and Pediatrics, Harvard Medical School (A.G.R.) - both in Boston; the Division of Infectious Diseases, Children's Hospital Los Angeles, and the Departments of Pediatrics and Molecular Microbiology and Immunology, University of Southern California, Los Angeles, Los Angeles (P.S.P.), the Division of Pediatric Hospital Medicine, UC San Diego-Rady Children's Hospital, San Diego (M.A.C.), the Department of Pediatrics, Divisions of Critical Care Medicine and Allergy, Immunology, and Bone Marrow Transplant, University of California, San Francisco, San Francisco (M.S.Z.), and the Division of Critical Care Medicine, UCSF Benioff Children's Hospital, Oakland (N.Z.C.) - all in California; the Department of Pediatrics, Baylor College of Medicine, Immunization Project, Texas Children's Hospital, Houston (J.A.B., L.C.S.); the Division of Critical Care Medicine, Department of Anesthesiology and Critical Care, Children's Hospital of Philadelphia, Philadelphia (K.C.); the Department of Pediatrics, Division of Infectious Diseases, University of Mississippi Medical Center, Jackson (C.V.H.); the Department of Pediatrics, Section of Critical Care Medicine, University of Colorado School of Medicine, and Children's Hospital Colorado, Aurora (A.B.M.); the Division of Critical Care Medicine, Department of Pediatrics, Northwestern University Feinberg School of Medicine, Ann and Robert H. Lurie Children's Hospital of Chicago, Chicago (B.M.C., K.N.M.); the Division of Pediatric Critical Care Medicine, Children's Hospital of Michigan, Central Michigan University, Detroit (S.M.H.), and the Division of Pediatric Critical Care Medicine, Department of Pediatrics, Mott Children's Hospital and University of Michigan, Ann Arbor (H.R.F.); the Section of Pediatric Critical Care, Department of Pediatrics, Arkansas Children's Hospital, Little Rock (K.I.); the Division of Pediatric Critical Care Medicine (E.H.M.), and the Department of Pediatrics (L.S.), Medical University of South Carolina, Charleston; the Department of Pediatrics, University of North Carolina at Chapel Hill Children's Hospital, Chapel Hill (S.P.S., T.C.W.); the Division of Pediatric Critical Care, Department of Pediatrics, Cooperman Barnabas Medical Center, Livingston, NJ (S.J.G.); the Division of Pediatric Infectious Diseases, Department of Pediatrics, Children's Mercy Kansas City, Kansas City, Missouri (J.E.S.); the Ryan White Center for Pediatric Infectious Disease and Global Health, Department of Pediatrics, Indiana University School of Medicine, Indianapolis (S.S.B.); the Department of Pediatrics, Division of Critical Care Medicine, University of Texas Southwestern, Children's Medical Center, Dallas (M.M.); the Division of Pediatric Critical Care, University of Minnesota Masonic Children's Hospital, Minneapolis (J.R.H.), and the Divisions of Pediatric Infectious Diseases and Pediatric Critical Care Medicine, Department of Pediatric and Adolescent Medicine, Mayo Clinic, Rochester (E.R.L.) - both in Minnesota; the Division of Pediatric Critical Care, Department of Pediatrics, University of Utah, Salt Lake City (H.C.); the Department of Pediatrics, Division of Cardiology, Louisiana State University Health Sciences Center and Children's Hospital of New Orleans, New Orleans (T.T.B.); the Division of Pediatric Critical Care, Department of Pediatrics, Children's Hospital and Medical Center, Omaha, NE (M.L.C.); and the Division of Pediatric Critical Care Medicine, Department of Pediatrics, University of Alabama at Birmingham, Birmingham (M.K.).; Irby K; From the Division of Pediatric Infectious Diseases, Department of Pediatrics, Vanderbilt University Medical Center, Nashville (N.B.H.); the Covid-19 Response Team, Centers for Disease Control and Prevention (S.M.O., A.M.P., S.M.G., K.N.P., A.P.C., M.M.P.), the Center for Childhood Infections and Vaccines of Children's Healthcare of Atlanta and the Department of Pediatrics, Emory University School of Medicine (S.K.), and the Division of Critical Care Medicine, Department of Pediatrics, Emory University School of Medicine, Children's Healthcare of Atlanta (K.M.T.) - all in Atlanta; the Department of Pediatrics, University of Cincinnati College of Medicine, Cincinnati Children's Hospital Medical Center, Cincinnati (M.A.S.), the Division of Pediatric Critical Care Medicine, Nationwide Children's Hospital, Columbus (K.E.B.), and the Division of Critical Care Medicine, Department of Pediatrics, Akron Children's Hospital, Akron (R.A.N.) - all in Ohio; the Department of Anesthesiology, Critical Care, and Pain Medicine, Boston Children's Hospital (M.M.N., A.G.R.), and the Departments of Anaesthesia and Pediatrics, Harvard Medical School (A.G.R.) - both in Boston; the Division of Infectious Diseases, Children's Hospital Los Angeles, and the Departments of Pediatrics and Molecular Microbiology and Immunology, University of Southern California, Los Angeles, Los Angeles (P.S.P.), the Division of Pediatric Hospital Medicine, UC San Diego-Rady Children's Hospital, San Diego (M.A.C.), the Department of Pediatrics, Divisions of Critical Care Medicine and Allergy, Immunology, and Bone Marrow Transplant, University of California, San Francisco, San Francisco (M.S.Z.), and the Division of Critical Care Medicine, UCSF Benioff Children's Hospital, Oakland (N.Z.C.) - all in California; the Department of Pediatrics, Baylor College of Medicine, Immunization Project, Texas Children's Hospital, Houston (J.A.B., L.C.S.); the Division of Critical Care Medicine, Department of Anesthesiology and Critical Care, Children's Hospital of Philadelphia, Philadelphia (K.C.); the Department of Pediatrics, Division of Infectious Diseases, University of Mississippi Medical Center, Jackson (C.V.H.); the Department of Pediatrics, Section of Critical Care Medicine, University of Colorado School of Medicine, and Children's Hospital Colorado, Aurora (A.B.M.); the Division of Critical Care Medicine, Department of Pediatrics, Northwestern University Feinberg School of Medicine, Ann and Robert H. Lurie Children's Hospital of Chicago, Chicago (B.M.C., K.N.M.); the Division of Pediatric Critical Care Medicine, Children's Hospital of Michigan, Central Michigan University, Detroit (S.M.H.), and the Division of Pediatric Critical Care Medicine, Department of Pediatrics, Mott Children's Hospital and University of Michigan, Ann Arbor (H.R.F.); the Section of Pediatric Critical Care, Department of Pediatrics, Arkansas Children's Hospital, Little Rock (K.I.); the Division of Pediatric Critical Care Medicine (E.H.M.), and the Department of Pediatrics (L.S.), Medical University of South Carolina, Charleston; the Department of Pediatrics, University of North Carolina at Chapel Hill Children's Hospital, Chapel Hill (S.P.S., T.C.W.); the Division of Pediatric Critical Care, Department of Pediatrics, Cooperman Barnabas Medical Center, Livingston, NJ (S.J.G.); the Division of Pediatric Infectious Diseases, Department of Pediatrics, Children's Mercy Kansas City, Kansas City, Missouri (J.E.S.); the Ryan White Center for Pediatric Infectious Disease and Global Health, Department of Pediatrics, Indiana University School of Medicine, Indianapolis (S.S.B.); the Department of Pediatrics, Division of Critical Care Medicine, University of Texas Southwestern, Children's Medical Center, Dallas (M.M.); the Division of Pediatric Critical Care, University of Minnesota Masonic Children's Hospital, Minneapolis (J.R.H.), and the Divisions of Pediatric Infectious Diseases and Pediatric Critical Care Medicine, Department of Pediatric and Adolescent Medicine, Mayo Clinic, Rochester (E.R.L.) - both in Minnesota; the Division of Pediatric Critical Care, Department of Pediatrics, University of Utah, Salt Lake City (H.C.); the Department of Pediatrics, Division of Cardiology, Louisiana State University Health Sciences Center and Children's Hospital of New Orleans, New Orleans (T.T.B.); the Division of Pediatric Critical Care, Department of Pediatrics, Children's Hospital and Medical Center, Omaha, NE (M.L.C.); and the Division of Pediatric Critical Care Medicine, Department of Pediatrics, University of Alabama at Birmingham, Birmingham (M.K.).; Nofziger RA; From the Division of Pediatric Infectious Diseases, Department of Pediatrics, Vanderbilt University Medical Center, Nashville (N.B.H.); the Covid-19 Response Team, Centers for Disease Control and Prevention (S.M.O., A.M.P., S.M.G., K.N.P., A.P.C., M.M.P.), the Center for Childhood Infections and Vaccines of Children's Healthcare of Atlanta and the Department of Pediatrics, Emory University School of Medicine (S.K.), and the Division of Critical Care Medicine, Department of Pediatrics, Emory University School of Medicine, Children's Healthcare of Atlanta (K.M.T.) - all in Atlanta; the Department of Pediatrics, University of Cincinnati College of Medicine, Cincinnati Children's Hospital Medical Center, Cincinnati (M.A.S.), the Division of Pediatric Critical Care Medicine, Nationwide Children's Hospital, Columbus (K.E.B.), and the Division of Critical Care Medicine, Department of Pediatrics, Akron Children's Hospital, Akron (R.A.N.) - all in Ohio; the Department of Anesthesiology, Critical Care, and Pain Medicine, Boston Children's Hospital (M.M.N., A.G.R.), and the Departments of Anaesthesia and Pediatrics, Harvard Medical School (A.G.R.) - both in Boston; the Division of Infectious Diseases, Children's Hospital Los Angeles, and the Departments of Pediatrics and Molecular Microbiology and Immunology, University of Southern California, Los Angeles, Los Angeles (P.S.P.), the Division of Pediatric Hospital Medicine, UC San Diego-Rady Children's Hospital, San Diego (M.A.C.), the Department of Pediatrics, Divisions of Critical Care Medicine and Allergy, Immunology, and Bone Marrow Transplant, University of California, San Francisco, San Francisco (M.S.Z.), and the Division of Critical Care Medicine, UCSF Benioff Children's Hospital, Oakland (N.Z.C.) - all in California; the Department of Pediatrics, Baylor College of Medicine, Immunization Project, Texas Children's Hospital, Houston (J.A.B., L.C.S.); the Division of Critical Care Medicine, Department of Anesthesiology and Critical Care, Children's Hospital of Philadelphia, Philadelphia (K.C.); the Department of Pediatrics, Division of Infectious Diseases, University of Mississippi Medical Center, Jackson (C.V.H.); the Department of Pediatrics, Section of Critical Care Medicine, University of Colorado School of Medicine, and Children's Hospital Colorado, Aurora (A.B.M.); the Division of Critical Care Medicine, Department of Pediatrics, Northwestern University Feinberg School of Medicine, Ann and Robert H. Lurie Children's Hospital of Chicago, Chicago (B.M.C., K.N.M.); the Division of Pediatric Critical Care Medicine, Children's Hospital of Michigan, Central Michigan University, Detroit (S.M.H.), and the Division of Pediatric Critical Care Medicine, Department of Pediatrics, Mott Children's Hospital and University of Michigan, Ann Arbor (H.R.F.); the Section of Pediatric Critical Care, Department of Pediatrics, Arkansas Children's Hospital, Little Rock (K.I.); the Division of Pediatric Critical Care Medicine (E.H.M.), and the Department of Pediatrics (L.S.), Medical University of South Carolina, Charleston; the Department of Pediatrics, University of North Carolina at Chapel Hill Children's Hospital, Chapel Hill (S.P.S., T.C.W.); the Division of Pediatric Critical Care, Department of Pediatrics, Cooperman Barnabas Medical Center, Livingston, NJ (S.J.G.); the Division of Pediatric Infectious Diseases, Department of Pediatrics, Children's Mercy Kansas City, Kansas City, Missouri (J.E.S.); the Ryan White Center for Pediatric Infectious Disease and Global Health, Department of Pediatrics, Indiana University School of Medicine, Indianapolis (S.S.B.); the Department of Pediatrics, Division of Critical Care Medicine, University of Texas Southwestern, Children's Medical Center, Dallas (M.M.); the Division of Pediatric Critical Care, University of Minnesota Masonic Children's Hospital, Minneapolis (J.R.H.), and the Divisions of Pediatric Infectious Diseases and Pediatric Critical Care Medicine, Department of Pediatric and Adolescent Medicine, Mayo Clinic, Rochester (E.R.L.) - both in Minnesota; the Division of Pediatric Critical Care, Department of Pediatrics, University of Utah, Salt Lake City (H.C.); the Department of Pediatrics, Division of Cardiology, Louisiana State University Health Sciences Center and Children's Hospital of New Orleans, New Orleans (T.T.B.); the Division of Pediatric Critical Care, Department of Pediatrics, Children's Hospital and Medical Center, Omaha, NE (M.L.C.); and the Division of Pediatric Critical Care Medicine, Department of Pediatrics, University of Alabama at Birmingham, Birmingham (M.K.).; Mack EH; From the Division of Pediatric Infectious Diseases, Department of Pediatrics, Vanderbilt University Medical Center, Nashville (N.B.H.); the Covid-19 Response Team, Centers for Disease Control and Prevention (S.M.O., A.M.P., S.M.G., K.N.P., A.P.C., M.M.P.), the Center for Childhood Infections and Vaccines of Children's Healthcare of Atlanta and the Department of Pediatrics, Emory University School of Medicine (S.K.), and the Division of Critical Care Medicine, Department of Pediatrics, Emory University School of Medicine, Children's Healthcare of Atlanta (K.M.T.) - all in Atlanta; the Department of Pediatrics, University of Cincinnati College of Medicine, Cincinnati Children's Hospital Medical Center, Cincinnati (M.A.S.), the Division of Pediatric Critical Care Medicine, Nationwide Children's Hospital, Columbus (K.E.B.), and the Division of Critical Care Medicine, Department of Pediatrics, Akron Children's Hospital, Akron (R.A.N.) - all in Ohio; the Department of Anesthesiology, Critical Care, and Pain Medicine, Boston Children's Hospital (M.M.N., A.G.R.), and the Departments of Anaesthesia and Pediatrics, Harvard Medical School (A.G.R.) - both in Boston; the Division of Infectious Diseases, Children's Hospital Los Angeles, and the Departments of Pediatrics and Molecular Microbiology and Immunology, University of Southern California, Los Angeles, Los Angeles (P.S.P.), the Division of Pediatric Hospital Medicine, UC San Diego-Rady Children's Hospital, San Diego (M.A.C.), the Department of Pediatrics, Divisions of Critical Care Medicine and Allergy, Immunology, and Bone Marrow Transplant, University of California, San Francisco, San Francisco (M.S.Z.), and the Division of Critical Care Medicine, UCSF Benioff Children's Hospital, Oakland (N.Z.C.) - all in California; the Department of Pediatrics, Baylor College of Medicine, Immunization Project, Texas Children's Hospital, Houston (J.A.B., L.C.S.); the Division of Critical Care Medicine, Department of Anesthesiology and Critical Care, Children's Hospital of Philadelphia, Philadelphia (K.C.); the Department of Pediatrics, Division of Infectious Diseases, University of Mississippi Medical Center, Jackson (C.V.H.); the Department of Pediatrics, Section of Critical Care Medicine, University of Colorado School of Medicine, and Children's Hospital Colorado, Aurora (A.B.M.); the Division of Critical Care Medicine, Department of Pediatrics, Northwestern University Feinberg School of Medicine, Ann and Robert H. Lurie Children's Hospital of Chicago, Chicago (B.M.C., K.N.M.); the Division of Pediatric Critical Care Medicine, Children's Hospital of Michigan, Central Michigan University, Detroit (S.M.H.), and the Division of Pediatric Critical Care Medicine, Department of Pediatrics, Mott Children's Hospital and University of Michigan, Ann Arbor (H.R.F.); the Section of Pediatric Critical Care, Department of Pediatrics, Arkansas Children's Hospital, Little Rock (K.I.); the Division of Pediatric Critical Care Medicine (E.H.M.), and the Department of Pediatrics (L.S.), Medical University of South Carolina, Charleston; the Department of Pediatrics, University of North Carolina at Chapel Hill Children's Hospital, Chapel Hill (S.P.S., T.C.W.); the Division of Pediatric Critical Care, Department of Pediatrics, Cooperman Barnabas Medical Center, Livingston, NJ (S.J.G.); the Division of Pediatric Infectious Diseases, Department of Pediatrics, Children's Mercy Kansas City, Kansas City, Missouri (J.E.S.); the Ryan White Center for Pediatric Infectious Disease and Global Health, Department of Pediatrics, Indiana University School of Medicine, Indianapolis (S.S.B.); the Department of Pediatrics, Division of Critical Care Medicine, University of Texas Southwestern, Children's Medical Center, Dallas (M.M.); the Division of Pediatric Critical Care, University of Minnesota Masonic Children's Hospital, Minneapolis (J.R.H.), and the Divisions of Pediatric Infectious Diseases and Pediatric Critical Care Medicine, Department of Pediatric and Adolescent Medicine, Mayo Clinic, Rochester (E.R.L.) - both in Minnesota; the Division of Pediatric Critical Care, Department of Pediatrics, University of Utah, Salt Lake City (H.C.); the Department of Pediatrics, Division of Cardiology, Louisiana State University Health Sciences Center and Children's Hospital of New Orleans, New Orleans (T.T.B.); the Division of Pediatric Critical Care, Department of Pediatrics, Children's Hospital and Medical Center, Omaha, NE (M.L.C.); and the Division of Pediatric Critical Care Medicine, Department of Pediatrics, University of Alabama at Birmingham, Birmingham (M.K.).; Smallcomb L; From the Division of Pediatric Infectious Diseases, Department of Pediatrics, Vanderbilt University Medical Center, Nashville (N.B.H.); the Covid-19 Response Team, Centers for Disease Control and Prevention (S.M.O., A.M.P., S.M.G., K.N.P., A.P.C., M.M.P.), the Center for Childhood Infections and Vaccines of Children's Healthcare of Atlanta and the Department of Pediatrics, Emory University School of Medicine (S.K.), and the Division of Critical Care Medicine, Department of Pediatrics, Emory University School of Medicine, Children's Healthcare of Atlanta (K.M.T.) - all in Atlanta; the Department of Pediatrics, University of Cincinnati College of Medicine, Cincinnati Children's Hospital Medical Center, Cincinnati (M.A.S.), the Division of Pediatric Critical Care Medicine, Nationwide Children's Hospital, Columbus (K.E.B.), and the Division of Critical Care Medicine, Department of Pediatrics, Akron Children's Hospital, Akron (R.A.N.) - all in Ohio; the Department of Anesthesiology, Critical Care, and Pain Medicine, Boston Children's Hospital (M.M.N., A.G.R.), and the Departments of Anaesthesia and Pediatrics, Harvard Medical School (A.G.R.) - both in Boston; the Division of Infectious Diseases, Children's Hospital Los Angeles, and the Departments of Pediatrics and Molecular Microbiology and Immunology, University of Southern California, Los Angeles, Los Angeles (P.S.P.), the Division of Pediatric Hospital Medicine, UC San Diego-Rady Children's Hospital, San Diego (M.A.C.), the Department of Pediatrics, Divisions of Critical Care Medicine and Allergy, Immunology, and Bone Marrow Transplant, University of California, San Francisco, San Francisco (M.S.Z.), and the Division of Critical Care Medicine, UCSF Benioff Children's Hospital, Oakland (N.Z.C.) - all in California; the Department of Pediatrics, Baylor College of Medicine, Immunization Project, Texas Children's Hospital, Houston (J.A.B., L.C.S.); the Division of Critical Care Medicine, Department of Anesthesiology and Critical Care, Children's Hospital of Philadelphia, Philadelphia (K.C.); the Department of Pediatrics, Division of Infectious Diseases, University of Mississippi Medical Center, Jackson (C.V.H.); the Department of Pediatrics, Section of Critical Care Medicine, University of Colorado School of Medicine, and Children's Hospital Colorado, Aurora (A.B.M.); the Division of Critical Care Medicine, Department of Pediatrics, Northwestern University Feinberg School of Medicine, Ann and Robert H. Lurie Children's Hospital of Chicago, Chicago (B.M.C., K.N.M.); the Division of Pediatric Critical Care Medicine, Children's Hospital of Michigan, Central Michigan University, Detroit (S.M.H.), and the Division of Pediatric Critical Care Medicine, Department of Pediatrics, Mott Children's Hospital and University of Michigan, Ann Arbor (H.R.F.); the Section of Pediatric Critical Care, Department of Pediatrics, Arkansas Children's Hospital, Little Rock (K.I.); the Division of Pediatric Critical Care Medicine (E.H.M.), and the Department of Pediatrics (L.S.), Medical University of South Carolina, Charleston; the Department of Pediatrics, University of North Carolina at Chapel Hill Children's Hospital, Chapel Hill (S.P.S., T.C.W.); the Division of Pediatric Critical Care, Department of Pediatrics, Cooperman Barnabas Medical Center, Livingston, NJ (S.J.G.); the Division of Pediatric Infectious Diseases, Department of Pediatrics, Children's Mercy Kansas City, Kansas City, Missouri (J.E.S.); the Ryan White Center for Pediatric Infectious Disease and Global Health, Department of Pediatrics, Indiana University School of Medicine, Indianapolis (S.S.B.); the Department of Pediatrics, Division of Critical Care Medicine, University of Texas Southwestern, Children's Medical Center, Dallas (M.M.); the Division of Pediatric Critical Care, University of Minnesota Masonic Children's Hospital, Minneapolis (J.R.H.), and the Divisions of Pediatric Infectious Diseases and Pediatric Critical Care Medicine, Department of Pediatric and Adolescent Medicine, Mayo Clinic, Rochester (E.R.L.) - both in Minnesota; the Division of Pediatric Critical Care, Department of Pediatrics, University of Utah, Salt Lake City (H.C.); the Department of Pediatrics, Division of Cardiology, Louisiana State University Health Sciences Center and Children's Hospital of New Orleans, New Orleans (T.T.B.); the Division of Pediatric Critical Care, Department of Pediatrics, Children's Hospital and Medical Center, Omaha, NE (M.L.C.); and the Division of Pediatric Critical Care Medicine, Department of Pediatrics, University of Alabama at Birmingham, Birmingham (M.K.).; Schwartz SP; From the Division of Pediatric Infectious Diseases, Department of Pediatrics, Vanderbilt University Medical Center, Nashville (N.B.H.); the Covid-19 Response Team, Centers for Disease Control and Prevention (S.M.O., A.M.P., S.M.G., K.N.P., A.P.C., M.M.P.), the Center for Childhood Infections and Vaccines of Children's Healthcare of Atlanta and the Department of Pediatrics, Emory University School of Medicine (S.K.), and the Division of Critical Care Medicine, Department of Pediatrics, Emory University School of Medicine, Children's Healthcare of Atlanta (K.M.T.) - all in Atlanta; the Department of Pediatrics, University of Cincinnati College of Medicine, Cincinnati Children's Hospital Medical Center, Cincinnati (M.A.S.), the Division of Pediatric Critical Care Medicine, Nationwide Children's Hospital, Columbus (K.E.B.), and the Division of Critical Care Medicine, Department of Pediatrics, Akron Children's Hospital, Akron (R.A.N.) - all in Ohio; the Department of Anesthesiology, Critical Care, and Pain Medicine, Boston Children's Hospital (M.M.N., A.G.R.), and the Departments of Anaesthesia and Pediatrics, Harvard Medical School (A.G.R.) - both in Boston; the Division of Infectious Diseases, Children's Hospital Los Angeles, and the Departments of Pediatrics and Molecular Microbiology and Immunology, University of Southern California, Los Angeles, Los Angeles (P.S.P.), the Division of Pediatric Hospital Medicine, UC San Diego-Rady Children's Hospital, San Diego (M.A.C.), the Department of Pediatrics, Divisions of Critical Care Medicine and Allergy, Immunology, and Bone Marrow Transplant, University of California, San Francisco, San Francisco (M.S.Z.), and the Division of Critical Care Medicine, UCSF Benioff Children's Hospital, Oakland (N.Z.C.) - all in California; the Department of Pediatrics, Baylor College of Medicine, Immunization Project, Texas Children's Hospital, Houston (J.A.B., L.C.S.); the Division of Critical Care Medicine, Department of Anesthesiology and Critical Care, Children's Hospital of Philadelphia, Philadelphia (K.C.); the Department of Pediatrics, Division of Infectious Diseases, University of Mississippi Medical Center, Jackson (C.V.H.); the Department of Pediatrics, Section of Critical Care Medicine, University of Colorado School of Medicine, and Children's Hospital Colorado, Aurora (A.B.M.); the Division of Critical Care Medicine, Department of Pediatrics, Northwestern University Feinberg School of Medicine, Ann and Robert H. Lurie Children's Hospital of Chicago, Chicago (B.M.C., K.N.M.); the Division of Pediatric Critical Care Medicine, Children's Hospital of Michigan, Central Michigan University, Detroit (S.M.H.), and the Division of Pediatric Critical Care Medicine, Department of Pediatrics, Mott Children's Hospital and University of Michigan, Ann Arbor (H.R.F.); the Section of Pediatric Critical Care, Department of Pediatrics, Arkansas Children's Hospital, Little Rock (K.I.); the Division of Pediatric Critical Care Medicine (E.H.M.), and the Department of Pediatrics (L.S.), Medical University of South Carolina, Charleston; the Department of Pediatrics, University of North Carolina at Chapel Hill Children's Hospital, Chapel Hill (S.P.S., T.C.W.); the Division of Pediatric Critical Care, Department of Pediatrics, Cooperman Barnabas Medical Center, Livingston, NJ (S.J.G.); the Division of Pediatric Infectious Diseases, Department of Pediatrics, Children's Mercy Kansas City, Kansas City, Missouri (J.E.S.); the Ryan White Center for Pediatric Infectious Disease and Global Health, Department of Pediatrics, Indiana University School of Medicine, Indianapolis (S.S.B.); the Department of Pediatrics, Division of Critical Care Medicine, University of Texas Southwestern, Children's Medical Center, Dallas (M.M.); the Division of Pediatric Critical Care, University of Minnesota Masonic Children's Hospital, Minneapolis (J.R.H.), and the Divisions of Pediatric Infectious Diseases and Pediatric Critical Care Medicine, Department of Pediatric and Adolescent Medicine, Mayo Clinic, Rochester (E.R.L.) - both in Minnesota; the Division of Pediatric Critical Care, Department of Pediatrics, University of Utah, Salt Lake City (H.C.); the Department of Pediatrics, Division of Cardiology, Louisiana State University Health Sciences Center and Children's Hospital of New Orleans, New Orleans (T.T.B.); the Division of Pediatric Critical Care, Department of Pediatrics, Children's Hospital and Medical Center, Omaha, NE (M.L.C.); and the Division of Pediatric Critical Care Medicine, Department of Pediatrics, University of Alabama at Birmingham, Birmingham (M.K.).; Walker TC; From the Division of Pediatric Infectious Diseases, Department of Pediatrics, Vanderbilt University Medical Center, Nashville (N.B.H.); the Covid-19 Response Team, Centers for Disease Control and Prevention (S.M.O., A.M.P., S.M.G., K.N.P., A.P.C., M.M.P.), the Center for Childhood Infections and Vaccines of Children's Healthcare of Atlanta and the Department of Pediatrics, Emory University School of Medicine (S.K.), and the Division of Critical Care Medicine, Department of Pediatrics, Emory University School of Medicine, Children's Healthcare of Atlanta (K.M.T.) - all in Atlanta; the Department of Pediatrics, University of Cincinnati College of Medicine, Cincinnati Children's Hospital Medical Center, Cincinnati (M.A.S.), the Division of Pediatric Critical Care Medicine, Nationwide Children's Hospital, Columbus (K.E.B.), and the Division of Critical Care Medicine, Department of Pediatrics, Akron Children's Hospital, Akron (R.A.N.) - all in Ohio; the Department of Anesthesiology, Critical Care, and Pain Medicine, Boston Children's Hospital (M.M.N., A.G.R.), and the Departments of Anaesthesia and Pediatrics, Harvard Medical School (A.G.R.) - both in Boston; the Division of Infectious Diseases, Children's Hospital Los Angeles, and the Departments of Pediatrics and Molecular Microbiology and Immunology, University of Southern California, Los Angeles, Los Angeles (P.S.P.), the Division of Pediatric Hospital Medicine, UC San Diego-Rady Children's Hospital, San Diego (M.A.C.), the Department of Pediatrics, Divisions of Critical Care Medicine and Allergy, Immunology, and Bone Marrow Transplant, University of California, San Francisco, San Francisco (M.S.Z.), and the Division of Critical Care Medicine, UCSF Benioff Children's Hospital, Oakland (N.Z.C.) - all in California; the Department of Pediatrics, Baylor College of Medicine, Immunization Project, Texas Children's Hospital, Houston (J.A.B., L.C.S.); the Division of Critical Care Medicine, Department of Anesthesiology and Critical Care, Children's Hospital of Philadelphia, Philadelphia (K.C.); the Department of Pediatrics, Division of Infectious Diseases, University of Mississippi Medical Center, Jackson (C.V.H.); the Department of Pediatrics, Section of Critical Care Medicine, University of Colorado School of Medicine, and Children's Hospital Colorado, Aurora (A.B.M.); the Division of Critical Care Medicine, Department of Pediatrics, Northwestern University Feinberg School of Medicine, Ann and Robert H. Lurie Children's Hospital of Chicago, Chicago (B.M.C., K.N.M.); the Division of Pediatric Critical Care Medicine, Children's Hospital of Michigan, Central Michigan University, Detroit (S.M.H.), and the Division of Pediatric Critical Care Medicine, Department of Pediatrics, Mott Children's Hospital and University of Michigan, Ann Arbor (H.R.F.); the Section of Pediatric Critical Care, Department of Pediatrics, Arkansas Children's Hospital, Little Rock (K.I.); the Division of Pediatric Critical Care Medicine (E.H.M.), and the Department of Pediatrics (L.S.), Medical University of South Carolina, Charleston; the Department of Pediatrics, University of North Carolina at Chapel Hill Children's Hospital, Chapel Hill (S.P.S., T.C.W.); the Division of Pediatric Critical Care, Department of Pediatrics, Cooperman Barnabas Medical Center, Livingston, NJ (S.J.G.); the Division of Pediatric Infectious Diseases, Department of Pediatrics, Children's Mercy Kansas City, Kansas City, Missouri (J.E.S.); the Ryan White Center for Pediatric Infectious Disease and Global Health, Department of Pediatrics, Indiana University School of Medicine, Indianapolis (S.S.B.); the Department of Pediatrics, Division of Critical Care Medicine, University of Texas Southwestern, Children's Medical Center, Dallas (M.M.); the Division of Pediatric Critical Care, University of Minnesota Masonic Children's Hospital, Minneapolis (J.R.H.), and the Divisions of Pediatric Infectious Diseases and Pediatric Critical Care Medicine, Department of Pediatric and Adolescent Medicine, Mayo Clinic, Rochester (E.R.L.) - both in Minnesota; the Division of Pediatric Critical Care, Department of Pediatrics, University of Utah, Salt Lake City (H.C.); the Department of Pediatrics, Division of Cardiology, Louisiana State University Health Sciences Center and Children's Hospital of New Orleans, New Orleans (T.T.B.); the Division of Pediatric Critical Care, Department of Pediatrics, Children's Hospital and Medical Center, Omaha, NE (M.L.C.); and the Division of Pediatric Critical Care Medicine, Department of Pediatrics, University of Alabama at Birmingham, Birmingham (M.K.).; Gertz SJ; From the Division of Pediatric Infectious Diseases, Department of Pediatrics, Vanderbilt University Medical Center, Nashville (N.B.H.); the Covid-19 Response Team, Centers for Disease Control and Prevention (S.M.O., A.M.P., S.M.G., K.N.P., A.P.C., M.M.P.), the Center for Childhood Infections and Vaccines of Children's Healthcare of Atlanta and the Department of Pediatrics, Emory University School of Medicine (S.K.), and the Division of Critical Care Medicine, Department of Pediatrics, Emory University School of Medicine, Children's Healthcare of Atlanta (K.M.T.) - all in Atlanta; the Department of Pediatrics, University of Cincinnati College of Medicine, Cincinnati Children's Hospital Medical Center, Cincinnati (M.A.S.), the Division of Pediatric Critical Care Medicine, Nationwide Children's Hospital, Columbus (K.E.B.), and the Division of Critical Care Medicine, Department of Pediatrics, Akron Children's Hospital, Akron (R.A.N.) - all in Ohio; the Department of Anesthesiology, Critical Care, and Pain Medicine, Boston Children's Hospital (M.M.N., A.G.R.), and the Departments of Anaesthesia and Pediatrics, Harvard Medical School (A.G.R.) - both in Boston; the Division of Infectious Diseases, Children's Hospital Los Angeles, and the Departments of Pediatrics and Molecular Microbiology and Immunology, University of Southern California, Los Angeles, Los Angeles (P.S.P.), the Division of Pediatric Hospital Medicine, UC San Diego-Rady Children's Hospital, San Diego (M.A.C.), the Department of Pediatrics, Divisions of Critical Care Medicine and Allergy, Immunology, and Bone Marrow Transplant, University of California, San Francisco, San Francisco (M.S.Z.), and the Division of Critical Care Medicine, UCSF Benioff Children's Hospital, Oakland (N.Z.C.) - all in California; the Department of Pediatrics, Baylor College of Medicine, Immunization Project, Texas Children's Hospital, Houston (J.A.B., L.C.S.); the Division of Critical Care Medicine, Department of Anesthesiology and Critical Care, Children's Hospital of Philadelphia, Philadelphia (K.C.); the Department of Pediatrics, Division of Infectious Diseases, University of Mississippi Medical Center, Jackson (C.V.H.); the Department of Pediatrics, Section of Critical Care Medicine, University of Colorado School of Medicine, and Children's Hospital Colorado, Aurora (A.B.M.); the Division of Critical Care Medicine, Department of Pediatrics, Northwestern University Feinberg School of Medicine, Ann and Robert H. Lurie Children's Hospital of Chicago, Chicago (B.M.C., K.N.M.); the Division of Pediatric Critical Care Medicine, Children's Hospital of Michigan, Central Michigan University, Detroit (S.M.H.), and the Division of Pediatric Critical Care Medicine, Department of Pediatrics, Mott Children's Hospital and University of Michigan, Ann Arbor (H.R.F.); the Section of Pediatric Critical Care, Department of Pediatrics, Arkansas Children's Hospital, Little Rock (K.I.); the Division of Pediatric Critical Care Medicine (E.H.M.), and the Department of Pediatrics (L.S.), Medical University of South Carolina, Charleston; the Department of Pediatrics, University of North Carolina at Chapel Hill Children's Hospital, Chapel Hill (S.P.S., T.C.W.); the Division of Pediatric Critical Care, Department of Pediatrics, Cooperman Barnabas Medical Center, Livingston, NJ (S.J.G.); the Division of Pediatric Infectious Diseases, Department of Pediatrics, Children's Mercy Kansas City, Kansas City, Missouri (J.E.S.); the Ryan White Center for Pediatric Infectious Disease and Global Health, Department of Pediatrics, Indiana University School of Medicine, Indianapolis (S.S.B.); the Department of Pediatrics, Division of Critical Care Medicine, University of Texas Southwestern, Children's Medical Center, Dallas (M.M.); the Division of Pediatric Critical Care, University of Minnesota Masonic Children's Hospital, Minneapolis (J.R.H.), and the Divisions of Pediatric Infectious Diseases and Pediatric Critical Care Medicine, Department of Pediatric and Adolescent Medicine, Mayo Clinic, Rochester (E.R.L.) - both in Minnesota; the Division of Pediatric Critical Care, Department of Pediatrics, University of Utah, Salt Lake City (H.C.); the Department of Pediatrics, Division of Cardiology, Louisiana State University Health Sciences Center and Children's Hospital of New Orleans, New Orleans (T.T.B.); the Division of Pediatric Critical Care, Department of Pediatrics, Children's Hospital and Medical Center, Omaha, NE (M.L.C.); and the Division of Pediatric Critical Care Medicine, Department of Pediatrics, University of Alabama at Birmingham, Birmingham (M.K.).; Schuster JE; From the Division of Pediatric Infectious Diseases, Department of Pediatrics, Vanderbilt University Medical Center, Nashville (N.B.H.); the Covid-19 Response Team, Centers for Disease Control and Prevention (S.M.O., A.M.P., S.M.G., K.N.P., A.P.C., M.M.P.), the Center for Childhood Infections and Vaccines of Children's Healthcare of Atlanta and the Department of Pediatrics, Emory University School of Medicine (S.K.), and the Division of Critical Care Medicine, Department of Pediatrics, Emory University School of Medicine, Children's Healthcare of Atlanta (K.M.T.) - all in Atlanta; the Department of Pediatrics, University of Cincinnati College of Medicine, Cincinnati Children's Hospital Medical Center, Cincinnati (M.A.S.), the Division of Pediatric Critical Care Medicine, Nationwide Children's Hospital, Columbus (K.E.B.), and the Division of Critical Care Medicine, Department of Pediatrics, Akron Children's Hospital, Akron (R.A.N.) - all in Ohio; the Department of Anesthesiology, Critical Care, and Pain Medicine, Boston Children's Hospital (M.M.N., A.G.R.), and the Departments of Anaesthesia and Pediatrics, Harvard Medical School (A.G.R.) - both in Boston; the Division of Infectious Diseases, Children's Hospital Los Angeles, and the Departments of Pediatrics and Molecular Microbiology and Immunology, University of Southern California, Los Angeles, Los Angeles (P.S.P.), the Division of Pediatric Hospital Medicine, UC San Diego-Rady Children's Hospital, San Diego (M.A.C.), the Department of Pediatrics, Divisions of Critical Care Medicine and Allergy, Immunology, and Bone Marrow Transplant, University of California, San Francisco, San Francisco (M.S.Z.), and the Division of Critical Care Medicine, UCSF Benioff Children's Hospital, Oakland (N.Z.C.) - all in California; the Department of Pediatrics, Baylor College of Medicine, Immunization Project, Texas Children's Hospital, Houston (J.A.B., L.C.S.); the Division of Critical Care Medicine, Department of Anesthesiology and Critical Care, Children's Hospital of Philadelphia, Philadelphia (K.C.); the Department of Pediatrics, Division of Infectious Diseases, University of Mississippi Medical Center, Jackson (C.V.H.); the Department of Pediatrics, Section of Critical Care Medicine, University of Colorado School of Medicine, and Children's Hospital Colorado, Aurora (A.B.M.); the Division of Critical Care Medicine, Department of Pediatrics, Northwestern University Feinberg School of Medicine, Ann and Robert H. Lurie Children's Hospital of Chicago, Chicago (B.M.C., K.N.M.); the Division of Pediatric Critical Care Medicine, Children's Hospital of Michigan, Central Michigan University, Detroit (S.M.H.), and the Division of Pediatric Critical Care Medicine, Department of Pediatrics, Mott Children's Hospital and University of Michigan, Ann Arbor (H.R.F.); the Section of Pediatric Critical Care, Department of Pediatrics, Arkansas Children's Hospital, Little Rock (K.I.); the Division of Pediatric Critical Care Medicine (E.H.M.), and the Department of Pediatrics (L.S.), Medical University of South Carolina, Charleston; the Department of Pediatrics, University of North Carolina at Chapel Hill Children's Hospital, Chapel Hill (S.P.S., T.C.W.); the Division of Pediatric Critical Care, Department of Pediatrics, Cooperman Barnabas Medical Center, Livingston, NJ (S.J.G.); the Division of Pediatric Infectious Diseases, Department of Pediatrics, Children's Mercy Kansas City, Kansas City, Missouri (J.E.S.); the Ryan White Center for Pediatric Infectious Disease and Global Health, Department of Pediatrics, Indiana University School of Medicine, Indianapolis (S.S.B.); the Department of Pediatrics, Division of Critical Care Medicine, University of Texas Southwestern, Children's Medical Center, Dallas (M.M.); the Division of Pediatric Critical Care, University of Minnesota Masonic Children's Hospital, Minneapolis (J.R.H.), and the Divisions of Pediatric Infectious Diseases and Pediatric Critical Care Medicine, Department of Pediatric and Adolescent Medicine, Mayo Clinic, Rochester (E.R.L.) - both in Minnesota; the Division of Pediatric Critical Care, Department of Pediatrics, University of Utah, Salt Lake City (H.C.); the Department of Pediatrics, Division of Cardiology, Louisiana State University Health Sciences Center and Children's Hospital of New Orleans, New Orleans (T.T.B.); the Division of Pediatric Critical Care, Department of Pediatrics, Children's Hospital and Medical Center, Omaha, NE (M.L.C.); and the Division of Pediatric Critical Care Medicine, Department of Pediatrics, University of Alabama at Birmingham, Birmingham (M.K.).; Kamidani S; From the Division of Pediatric Infectious Diseases, Department of Pediatrics, Vanderbilt University Medical Center, Nashville (N.B.H.); the Covid-19 Response Team, Centers for Disease Control and Prevention (S.M.O., A.M.P., S.M.G., K.N.P., A.P.C., M.M.P.), the Center for Childhood Infections and Vaccines of Children's Healthcare of Atlanta and the Department of Pediatrics, Emory University School of Medicine (S.K.), and the Division of Critical Care Medicine, Department of Pediatrics, Emory University School of Medicine, Children's Healthcare of Atlanta (K.M.T.) - all in Atlanta; the Department of Pediatrics, University of Cincinnati College of Medicine, Cincinnati Children's Hospital Medical Center, Cincinnati (M.A.S.), the Division of Pediatric Critical Care Medicine, Nationwide Children's Hospital, Columbus (K.E.B.), and the Division of Critical Care Medicine, Department of Pediatrics, Akron Children's Hospital, Akron (R.A.N.) - all in Ohio; the Department of Anesthesiology, Critical Care, and Pain Medicine, Boston Children's Hospital (M.M.N., A.G.R.), and the Departments of Anaesthesia and Pediatrics, Harvard Medical School (A.G.R.) - both in Boston; the Division of Infectious Diseases, Children's Hospital Los Angeles, and the Departments of Pediatrics and Molecular Microbiology and Immunology, University of Southern California, Los Angeles, Los Angeles (P.S.P.), the Division of Pediatric Hospital Medicine, UC San Diego-Rady Children's Hospital, San Diego (M.A.C.), the Department of Pediatrics, Divisions of Critical Care Medicine and Allergy, Immunology, and Bone Marrow Transplant, University of California, San Francisco, San Francisco (M.S.Z.), and the Division of Critical Care Medicine, UCSF Benioff Children's Hospital, Oakland (N.Z.C.) - all in California; the Department of Pediatrics, Baylor College of Medicine, Immunization Project, Texas Children's Hospital, Houston (J.A.B., L.C.S.); the Division of Critical Care Medicine, Department of Anesthesiology and Critical Care, Children's Hospital of Philadelphia, Philadelphia (K.C.); the Department of Pediatrics, Division of Infectious Diseases, University of Mississippi Medical Center, Jackson (C.V.H.); the Department of Pediatrics, Section of Critical Care Medicine, University of Colorado School of Medicine, and Children's Hospital Colorado, Aurora (A.B.M.); the Division of Critical Care Medicine, Department of Pediatrics, Northwestern University Feinberg School of Medicine, Ann and Robert H. Lurie Children's Hospital of Chicago, Chicago (B.M.C., K.N.M.); the Division of Pediatric Critical Care Medicine, Children's Hospital of Michigan, Central Michigan University, Detroit (S.M.H.), and the Division of Pediatric Critical Care Medicine, Department of Pediatrics, Mott Children's Hospital and University of Michigan, Ann Arbor (H.R.F.); the Section of Pediatric Critical Care, Department of Pediatrics, Arkansas Children's Hospital, Little Rock (K.I.); the Division of Pediatric Critical Care Medicine (E.H.M.), and the Department of Pediatrics (L.S.), Medical University of South Carolina, Charleston; the Department of Pediatrics, University of North Carolina at Chapel Hill Children's Hospital, Chapel Hill (S.P.S., T.C.W.); the Division of Pediatric Critical Care, Department of Pediatrics, Cooperman Barnabas Medical Center, Livingston, NJ (S.J.G.); the Division of Pediatric Infectious Diseases, Department of Pediatrics, Children's Mercy Kansas City, Kansas City, Missouri (J.E.S.); the Ryan White Center for Pediatric Infectious Disease and Global Health, Department of Pediatrics, Indiana University School of Medicine, Indianapolis (S.S.B.); the Department of Pediatrics, Division of Critical Care Medicine, University of Texas Southwestern, Children's Medical Center, Dallas (M.M.); the Division of Pediatric Critical Care, University of Minnesota Masonic Children's Hospital, Minneapolis (J.R.H.), and the Divisions of Pediatric Infectious Diseases and Pediatric Critical Care Medicine, Department of Pediatric and Adolescent Medicine, Mayo Clinic, Rochester (E.R.L.) - both in Minnesota; the Division of Pediatric Critical Care, Department of Pediatrics, University of Utah, Salt Lake City (H.C.); the Department of Pediatrics, Division of Cardiology, Louisiana State University Health Sciences Center and Children's Hospital of New Orleans, New Orleans (T.T.B.); the Division of Pediatric Critical Care, Department of Pediatrics, Children's Hospital and Medical Center, Omaha, NE (M.L.C.); and the Division of Pediatric Critical Care Medicine, Department of Pediatrics, University of Alabama at Birmingham, Birmingham (M.K.).; Tarquinio KM; From the Division of Pediatric Infectious Diseases, Department of Pediatrics, Vanderbilt University Medical Center, Nashville (N.B.H.); the Covid-19 Response Team, Centers for Disease Control and Prevention (S.M.O., A.M.P., S.M.G., K.N.P., A.P.C., M.M.P.), the Center for Childhood Infections and Vaccines of Children's Healthcare of Atlanta and the Department of Pediatrics, Emory University School of Medicine (S.K.), and the Division of Critical Care Medicine, Department of Pediatrics, Emory University School of Medicine, Children's Healthcare of Atlanta (K.M.T.) - all in Atlanta; the Department of Pediatrics, University of Cincinnati College of Medicine, Cincinnati Children's Hospital Medical Center, Cincinnati (M.A.S.), the Division of Pediatric Critical Care Medicine, Nationwide Children's Hospital, Columbus (K.E.B.), and the Division of Critical Care Medicine, Department of Pediatrics, Akron Children's Hospital, Akron (R.A.N.) - all in Ohio; the Department of Anesthesiology, Critical Care, and Pain Medicine, Boston Children's Hospital (M.M.N., A.G.R.), and the Departments of Anaesthesia and Pediatrics, Harvard Medical School (A.G.R.) - both in Boston; the Division of Infectious Diseases, Children's Hospital Los Angeles, and the Departments of Pediatrics and Molecular Microbiology and Immunology, University of Southern California, Los Angeles, Los Angeles (P.S.P.), the Division of Pediatric Hospital Medicine, UC San Diego-Rady Children's Hospital, San Diego (M.A.C.), the Department of Pediatrics, Divisions of Critical Care Medicine and Allergy, Immunology, and Bone Marrow Transplant, University of California, San Francisco, San Francisco (M.S.Z.), and the Division of Critical Care Medicine, UCSF Benioff Children's Hospital, Oakland (N.Z.C.) - all in California; the Department of Pediatrics, Baylor College of Medicine, Immunization Project, Texas Children's Hospital, Houston (J.A.B., L.C.S.); the Division of Critical Care Medicine, Department of Anesthesiology and Critical Care, Children's Hospital of Philadelphia, Philadelphia (K.C.); the Department of Pediatrics, Division of Infectious Diseases, University of Mississippi Medical Center, Jackson (C.V.H.); the Department of Pediatrics, Section of Critical Care Medicine, University of Colorado School of Medicine, and Children's Hospital Colorado, Aurora (A.B.M.); the Division of Critical Care Medicine, Department of Pediatrics, Northwestern University Feinberg School of Medicine, Ann and Robert H. Lurie Children's Hospital of Chicago, Chicago (B.M.C., K.N.M.); the Division of Pediatric Critical Care Medicine, Children's Hospital of Michigan, Central Michigan University, Detroit (S.M.H.), and the Division of Pediatric Critical Care Medicine, Department of Pediatrics, Mott Children's Hospital and University of Michigan, Ann Arbor (H.R.F.); the Section of Pediatric Critical Care, Department of Pediatrics, Arkansas Children's Hospital, Little Rock (K.I.); the Division of Pediatric Critical Care Medicine (E.H.M.), and the Department of Pediatrics (L.S.), Medical University of South Carolina, Charleston; the Department of Pediatrics, University of North Carolina at Chapel Hill Children's Hospital, Chapel Hill (S.P.S., T.C.W.); the Division of Pediatric Critical Care, Department of Pediatrics, Cooperman Barnabas Medical Center, Livingston, NJ (S.J.G.); the Division of Pediatric Infectious Diseases, Department of Pediatrics, Children's Mercy Kansas City, Kansas City, Missouri (J.E.S.); the Ryan White Center for Pediatric Infectious Disease and Global Health, Department of Pediatrics, Indiana University School of Medicine, Indianapolis (S.S.B.); the Department of Pediatrics, Division of Critical Care Medicine, University of Texas Southwestern, Children's Medical Center, Dallas (M.M.); the Division of Pediatric Critical Care, University of Minnesota Masonic Children's Hospital, Minneapolis (J.R.H.), and the Divisions of Pediatric Infectious Diseases and Pediatric Critical Care Medicine, Department of Pediatric and Adolescent Medicine, Mayo Clinic, Rochester (E.R.L.) - both in Minnesota; the Division of Pediatric Critical Care, Department of Pediatrics, University of Utah, Salt Lake City (H.C.); the Department of Pediatrics, Division of Cardiology, Louisiana State University Health Sciences Center and Children's Hospital of New Orleans, New Orleans (T.T.B.); the Division of Pediatric Critical Care, Department of Pediatrics, Children's Hospital and Medical Center, Omaha, NE (M.L.C.); and the Division of Pediatric Critical Care Medicine, Department of Pediatrics, University of Alabama at Birmingham, Birmingham (M.K.).; Bhumbra SS; From the Division of Pediatric Infectious Diseases, Department of Pediatrics, Vanderbilt University Medical Center, Nashville (N.B.H.); the Covid-19 Response Team, Centers for Disease Control and Prevention (S.M.O., A.M.P., S.M.G., K.N.P., A.P.C., M.M.P.), the Center for Childhood Infections and Vaccines of Children's Healthcare of Atlanta and the Department of Pediatrics, Emory University School of Medicine (S.K.), and the Division of Critical Care Medicine, Department of Pediatrics, Emory University School of Medicine, Children's Healthcare of Atlanta (K.M.T.) - all in Atlanta; the Department of Pediatrics, University of Cincinnati College of Medicine, Cincinnati Children's Hospital Medical Center, Cincinnati (M.A.S.), the Division of Pediatric Critical Care Medicine, Nationwide Children's Hospital, Columbus (K.E.B.), and the Division of Critical Care Medicine, Department of Pediatrics, Akron Children's Hospital, Akron (R.A.N.) - all in Ohio; the Department of Anesthesiology, Critical Care, and Pain Medicine, Boston Children's Hospital (M.M.N., A.G.R.), and the Departments of Anaesthesia and Pediatrics, Harvard Medical School (A.G.R.) - both in Boston; the Division of Infectious Diseases, Children's Hospital Los Angeles, and the Departments of Pediatrics and Molecular Microbiology and Immunology, University of Southern California, Los Angeles, Los Angeles (P.S.P.), the Division of Pediatric Hospital Medicine, UC San Diego-Rady Children's Hospital, San Diego (M.A.C.), the Department of Pediatrics, Divisions of Critical Care Medicine and Allergy, Immunology, and Bone Marrow Transplant, University of California, San Francisco, San Francisco (M.S.Z.), and the Division of Critical Care Medicine, UCSF Benioff Children's Hospital, Oakland (N.Z.C.) - all in California; the Department of Pediatrics, Baylor College of Medicine, Immunization Project, Texas Children's Hospital, Houston (J.A.B., L.C.S.); the Division of Critical Care Medicine, Department of Anesthesiology and Critical Care, Children's Hospital of Philadelphia, Philadelphia (K.C.); the Department of Pediatrics, Division of Infectious Diseases, University of Mississippi Medical Center, Jackson (C.V.H.); the Department of Pediatrics, Section of Critical Care Medicine, University of Colorado School of Medicine, and Children's Hospital Colorado, Aurora (A.B.M.); the Division of Critical Care Medicine, Department of Pediatrics, Northwestern University Feinberg School of Medicine, Ann and Robert H. Lurie Children's Hospital of Chicago, Chicago (B.M.C., K.N.M.); the Division of Pediatric Critical Care Medicine, Children's Hospital of Michigan, Central Michigan University, Detroit (S.M.H.), and the Division of Pediatric Critical Care Medicine, Department of Pediatrics, Mott Children's Hospital and University of Michigan, Ann Arbor (H.R.F.); the Section of Pediatric Critical Care, Department of Pediatrics, Arkansas Children's Hospital, Little Rock (K.I.); the Division of Pediatric Critical Care Medicine (E.H.M.), and the Department of Pediatrics (L.S.), Medical University of South Carolina, Charleston; the Department of Pediatrics, University of North Carolina at Chapel Hill Children's Hospital, Chapel Hill (S.P.S., T.C.W.); the Division of Pediatric Critical Care, Department of Pediatrics, Cooperman Barnabas Medical Center, Livingston, NJ (S.J.G.); the Division of Pediatric Infectious Diseases, Department of Pediatrics, Children's Mercy Kansas City, Kansas City, Missouri (J.E.S.); the Ryan White Center for Pediatric Infectious Disease and Global Health, Department of Pediatrics, Indiana University School of Medicine, Indianapolis (S.S.B.); the Department of Pediatrics, Division of Critical Care Medicine, University of Texas Southwestern, Children's Medical Center, Dallas (M.M.); the Division of Pediatric Critical Care, University of Minnesota Masonic Children's Hospital, Minneapolis (J.R.H.), and the Divisions of Pediatric Infectious Diseases and Pediatric Critical Care Medicine, Department of Pediatric and Adolescent Medicine, Mayo Clinic, Rochester (E.R.L.) - both in Minnesota; the Division of Pediatric Critical Care, Department of Pediatrics, University of Utah, Salt Lake City (H.C.); the Department of Pediatrics, Division of Cardiology, Louisiana State University Health Sciences Center and Children's Hospital of New Orleans, New Orleans (T.T.B.); the Division of Pediatric Critical Care, Department of Pediatrics, Children's Hospital and Medical Center, Omaha, NE (M.L.C.); and the Division of Pediatric Critical Care Medicine, Department of Pediatrics, University of Alabama at Birmingham, Birmingham (M.K.).; Maamari M; From the Division of Pediatric Infectious Diseases, Department of Pediatrics, Vanderbilt University Medical Center, Nashville (N.B.H.); the Covid-19 Response Team, Centers for Disease Control and Prevention (S.M.O., A.M.P., S.M.G., K.N.P., A.P.C., M.M.P.), the Center for Childhood Infections and Vaccines of Children's Healthcare of Atlanta and the Department of Pediatrics, Emory University School of Medicine (S.K.), and the Division of Critical Care Medicine, Department of Pediatrics, Emory University School of Medicine, Children's Healthcare of Atlanta (K.M.T.) - all in Atlanta; the Department of Pediatrics, University of Cincinnati College of Medicine, Cincinnati Children's Hospital Medical Center, Cincinnati (M.A.S.), the Division of Pediatric Critical Care Medicine, Nationwide Children's Hospital, Columbus (K.E.B.), and the Division of Critical Care Medicine, Department of Pediatrics, Akron Children's Hospital, Akron (R.A.N.) - all in Ohio; the Department of Anesthesiology, Critical Care, and Pain Medicine, Boston Children's Hospital (M.M.N., A.G.R.), and the Departments of Anaesthesia and Pediatrics, Harvard Medical School (A.G.R.) - both in Boston; the Division of Infectious Diseases, Children's Hospital Los Angeles, and the Departments of Pediatrics and Molecular Microbiology and Immunology, University of Southern California, Los Angeles, Los Angeles (P.S.P.), the Division of Pediatric Hospital Medicine, UC San Diego-Rady Children's Hospital, San Diego (M.A.C.), the Department of Pediatrics, Divisions of Critical Care Medicine and Allergy, Immunology, and Bone Marrow Transplant, University of California, San Francisco, San Francisco (M.S.Z.), and the Division of Critical Care Medicine, UCSF Benioff Children's Hospital, Oakland (N.Z.C.) - all in California; the Department of Pediatrics, Baylor College of Medicine, Immunization Project, Texas Children's Hospital, Houston (J.A.B., L.C.S.); the Division of Critical Care Medicine, Department of Anesthesiology and Critical Care, Children's Hospital of Philadelphia, Philadelphia (K.C.); the Department of Pediatrics, Division of Infectious Diseases, University of Mississippi Medical Center, Jackson (C.V.H.); the Department of Pediatrics, Section of Critical Care Medicine, University of Colorado School of Medicine, and Children's Hospital Colorado, Aurora (A.B.M.); the Division of Critical Care Medicine, Department of Pediatrics, Northwestern University Feinberg School of Medicine, Ann and Robert H. Lurie Children's Hospital of Chicago, Chicago (B.M.C., K.N.M.); the Division of Pediatric Critical Care Medicine, Children's Hospital of Michigan, Central Michigan University, Detroit (S.M.H.), and the Division of Pediatric Critical Care Medicine, Department of Pediatrics, Mott Children's Hospital and University of Michigan, Ann Arbor (H.R.F.); the Section of Pediatric Critical Care, Department of Pediatrics, Arkansas Children's Hospital, Little Rock (K.I.); the Division of Pediatric Critical Care Medicine (E.H.M.), and the Department of Pediatrics (L.S.), Medical University of South Carolina, Charleston; the Department of Pediatrics, University of North Carolina at Chapel Hill Children's Hospital, Chapel Hill (S.P.S., T.C.W.); the Division of Pediatric Critical Care, Department of Pediatrics, Cooperman Barnabas Medical Center, Livingston, NJ (S.J.G.); the Division of Pediatric Infectious Diseases, Department of Pediatrics, Children's Mercy Kansas City, Kansas City, Missouri (J.E.S.); the Ryan White Center for Pediatric Infectious Disease and Global Health, Department of Pediatrics, Indiana University School of Medicine, Indianapolis (S.S.B.); the Department of Pediatrics, Division of Critical Care Medicine, University of Texas Southwestern, Children's Medical Center, Dallas (M.M.); the Division of Pediatric Critical Care, University of Minnesota Masonic Children's Hospital, Minneapolis (J.R.H.), and the Divisions of Pediatric Infectious Diseases and Pediatric Critical Care Medicine, Department of Pediatric and Adolescent Medicine, Mayo Clinic, Rochester (E.R.L.) - both in Minnesota; the Division of Pediatric Critical Care, Department of Pediatrics, University of Utah, Salt Lake City (H.C.); the Department of Pediatrics, Division of Cardiology, Louisiana State University Health Sciences Center and Children's Hospital of New Orleans, New Orleans (T.T.B.); the Division of Pediatric Critical Care, Department of Pediatrics, Children's Hospital and Medical Center, Omaha, NE (M.L.C.); and the Division of Pediatric Critical Care Medicine, Department of Pediatrics, University of Alabama at Birmingham, Birmingham (M.K.).; Hume JR; From the Division of Pediatric Infectious Diseases, Department of Pediatrics, Vanderbilt University Medical Center, Nashville (N.B.H.); the Covid-19 Response Team, Centers for Disease Control and Prevention (S.M.O., A.M.P., S.M.G., K.N.P., A.P.C., M.M.P.), the Center for Childhood Infections and Vaccines of Children's Healthcare of Atlanta and the Department of Pediatrics, Emory University School of Medicine (S.K.), and the Division of Critical Care Medicine, Department of Pediatrics, Emory University School of Medicine, Children's Healthcare of Atlanta (K.M.T.) - all in Atlanta; the Department of Pediatrics, University of Cincinnati College of Medicine, Cincinnati Children's Hospital Medical Center, Cincinnati (M.A.S.), the Division of Pediatric Critical Care Medicine, Nationwide Children's Hospital, Columbus (K.E.B.), and the Division of Critical Care Medicine, Department of Pediatrics, Akron Children's Hospital, Akron (R.A.N.) - all in Ohio; the Department of Anesthesiology, Critical Care, and Pain Medicine, Boston Children's Hospital (M.M.N., A.G.R.), and the Departments of Anaesthesia and Pediatrics, Harvard Medical School (A.G.R.) - both in Boston; the Division of Infectious Diseases, Children's Hospital Los Angeles, and the Departments of Pediatrics and Molecular Microbiology and Immunology, University of Southern California, Los Angeles, Los Angeles (P.S.P.), the Division of Pediatric Hospital Medicine, UC San Diego-Rady Children's Hospital, San Diego (M.A.C.), the Department of Pediatrics, Divisions of Critical Care Medicine and Allergy, Immunology, and Bone Marrow Transplant, University of California, San Francisco, San Francisco (M.S.Z.), and the Division of Critical Care Medicine, UCSF Benioff Children's Hospital, Oakland (N.Z.C.) - all in California; the Department of Pediatrics, Baylor College of Medicine, Immunization Project, Texas Children's Hospital, Houston (J.A.B., L.C.S.); the Division of Critical Care Medicine, Department of Anesthesiology and Critical Care, Children's Hospital of Philadelphia, Philadelphia (K.C.); the Department of Pediatrics, Division of Infectious Diseases, University of Mississippi Medical Center, Jackson (C.V.H.); the Department of Pediatrics, Section of Critical Care Medicine, University of Colorado School of Medicine, and Children's Hospital Colorado, Aurora (A.B.M.); the Division of Critical Care Medicine, Department of Pediatrics, Northwestern University Feinberg School of Medicine, Ann and Robert H. Lurie Children's Hospital of Chicago, Chicago (B.M.C., K.N.M.); the Division of Pediatric Critical Care Medicine, Children's Hospital of Michigan, Central Michigan University, Detroit (S.M.H.), and the Division of Pediatric Critical Care Medicine, Department of Pediatrics, Mott Children's Hospital and University of Michigan, Ann Arbor (H.R.F.); the Section of Pediatric Critical Care, Department of Pediatrics, Arkansas Children's Hospital, Little Rock (K.I.); the Division of Pediatric Critical Care Medicine (E.H.M.), and the Department of Pediatrics (L.S.), Medical University of South Carolina, Charleston; the Department of Pediatrics, University of North Carolina at Chapel Hill Children's Hospital, Chapel Hill (S.P.S., T.C.W.); the Division of Pediatric Critical Care, Department of Pediatrics, Cooperman Barnabas Medical Center, Livingston, NJ (S.J.G.); the Division of Pediatric Infectious Diseases, Department of Pediatrics, Children's Mercy Kansas City, Kansas City, Missouri (J.E.S.); the Ryan White Center for Pediatric Infectious Disease and Global Health, Department of Pediatrics, Indiana University School of Medicine, Indianapolis (S.S.B.); the Department of Pediatrics, Division of Critical Care Medicine, University of Texas Southwestern, Children's Medical Center, Dallas (M.M.); the Division of Pediatric Critical Care, University of Minnesota Masonic Children's Hospital, Minneapolis (J.R.H.), and the Divisions of Pediatric Infectious Diseases and Pediatric Critical Care Medicine, Department of Pediatric and Adolescent Medicine, Mayo Clinic, Rochester (E.R.L.) - both in Minnesota; the Division of Pediatric Critical Care, Department of Pediatrics, University of Utah, Salt Lake City (H.C.); the Department of Pediatrics, Division of Cardiology, Louisiana State University Health Sciences Center and Children's Hospital of New Orleans, New Orleans (T.T.B.); the Division of Pediatric Critical Care, Department of Pediatrics, Children's Hospital and Medical Center, Omaha, NE (M.L.C.); and the Division of Pediatric Critical Care Medicine, Department of Pediatrics, University of Alabama at Birmingham, Birmingham (M.K.).; Crandall H; From the Division of Pediatric Infectious Diseases, Department of Pediatrics, Vanderbilt University Medical Center, Nashville (N.B.H.); the Covid-19 Response Team, Centers for Disease Control and Prevention (S.M.O., A.M.P., S.M.G., K.N.P., A.P.C., M.M.P.), the Center for Childhood Infections and Vaccines of Children's Healthcare of Atlanta and the Department of Pediatrics, Emory University School of Medicine (S.K.), and the Division of Critical Care Medicine, Department of Pediatrics, Emory University School of Medicine, Children's Healthcare of Atlanta (K.M.T.) - all in Atlanta; the Department of Pediatrics, University of Cincinnati College of Medicine, Cincinnati Children's Hospital Medical Center, Cincinnati (M.A.S.), the Division of Pediatric Critical Care Medicine, Nationwide Children's Hospital, Columbus (K.E.B.), and the Division of Critical Care Medicine, Department of Pediatrics, Akron Children's Hospital, Akron (R.A.N.) - all in Ohio; the Department of Anesthesiology, Critical Care, and Pain Medicine, Boston Children's Hospital (M.M.N., A.G.R.), and the Departments of Anaesthesia and Pediatrics, Harvard Medical School (A.G.R.) - both in Boston; the Division of Infectious Diseases, Children's Hospital Los Angeles, and the Departments of Pediatrics and Molecular Microbiology and Immunology, University of Southern California, Los Angeles, Los Angeles (P.S.P.), the Division of Pediatric Hospital Medicine, UC San Diego-Rady Children's Hospital, San Diego (M.A.C.), the Department of Pediatrics, Divisions of Critical Care Medicine and Allergy, Immunology, and Bone Marrow Transplant, University of California, San Francisco, San Francisco (M.S.Z.), and the Division of Critical Care Medicine, UCSF Benioff Children's Hospital, Oakland (N.Z.C.) - all in California; the Department of Pediatrics, Baylor College of Medicine, Immunization Project, Texas Children's Hospital, Houston (J.A.B., L.C.S.); the Division of Critical Care Medicine, Department of Anesthesiology and Critical Care, Children's Hospital of Philadelphia, Philadelphia (K.C.); the Department of Pediatrics, Division of Infectious Diseases, University of Mississippi Medical Center, Jackson (C.V.H.); the Department of Pediatrics, Section of Critical Care Medicine, University of Colorado School of Medicine, and Children's Hospital Colorado, Aurora (A.B.M.); the Division of Critical Care Medicine, Department of Pediatrics, Northwestern University Feinberg School of Medicine, Ann and Robert H. Lurie Children's Hospital of Chicago, Chicago (B.M.C., K.N.M.); the Division of Pediatric Critical Care Medicine, Children's Hospital of Michigan, Central Michigan University, Detroit (S.M.H.), and the Division of Pediatric Critical Care Medicine, Department of Pediatrics, Mott Children's Hospital and University of Michigan, Ann Arbor (H.R.F.); the Section of Pediatric Critical Care, Department of Pediatrics, Arkansas Children's Hospital, Little Rock (K.I.); the Division of Pediatric Critical Care Medicine (E.H.M.), and the Department of Pediatrics (L.S.), Medical University of South Carolina, Charleston; the Department of Pediatrics, University of North Carolina at Chapel Hill Children's Hospital, Chapel Hill (S.P.S., T.C.W.); the Division of Pediatric Critical Care, Department of Pediatrics, Cooperman Barnabas Medical Center, Livingston, NJ (S.J.G.); the Division of Pediatric Infectious Diseases, Department of Pediatrics, Children's Mercy Kansas City, Kansas City, Missouri (J.E.S.); the Ryan White Center for Pediatric Infectious Disease and Global Health, Department of Pediatrics, Indiana University School of Medicine, Indianapolis (S.S.B.); the Department of Pediatrics, Division of Critical Care Medicine, University of Texas Southwestern, Children's Medical Center, Dallas (M.M.); the Division of Pediatric Critical Care, University of Minnesota Masonic Children's Hospital, Minneapolis (J.R.H.), and the Divisions of Pediatric Infectious Diseases and Pediatric Critical Care Medicine, Department of Pediatric and Adolescent Medicine, Mayo Clinic, Rochester (E.R.L.) - both in Minnesota; the Division of Pediatric Critical Care, Department of Pediatrics, University of Utah, Salt Lake City (H.C.); the Department of Pediatrics, Division of Cardiology, Louisiana State University Health Sciences Center and Children's Hospital of New Orleans, New Orleans (T.T.B.); the Division of Pediatric Critical Care, Department of Pediatrics, Children's Hospital and Medical Center, Omaha, NE (M.L.C.); and the Division of Pediatric Critical Care Medicine, Department of Pediatrics, University of Alabama at Birmingham, Birmingham (M.K.).; Levy ER; From the Division of Pediatric Infectious Diseases, Department of Pediatrics, Vanderbilt University Medical Center, Nashville (N.B.H.); the Covid-19 Response Team, Centers for Disease Control and Prevention (S.M.O., A.M.P., S.M.G., K.N.P., A.P.C., M.M.P.), the Center for Childhood Infections and Vaccines of Children's Healthcare of Atlanta and the Department of Pediatrics, Emory University School of Medicine (S.K.), and the Division of Critical Care Medicine, Department of Pediatrics, Emory University School of Medicine, Children's Healthcare of Atlanta (K.M.T.) - all in Atlanta; the Department of Pediatrics, University of Cincinnati College of Medicine, Cincinnati Children's Hospital Medical Center, Cincinnati (M.A.S.), the Division of Pediatric Critical Care Medicine, Nationwide Children's Hospital, Columbus (K.E.B.), and the Division of Critical Care Medicine, Department of Pediatrics, Akron Children's Hospital, Akron (R.A.N.) - all in Ohio; the Department of Anesthesiology, Critical Care, and Pain Medicine, Boston Children's Hospital (M.M.N., A.G.R.), and the Departments of Anaesthesia and Pediatrics, Harvard Medical School (A.G.R.) - both in Boston; the Division of Infectious Diseases, Children's Hospital Los Angeles, and the Departments of Pediatrics and Molecular Microbiology and Immunology, University of Southern California, Los Angeles, Los Angeles (P.S.P.), the Division of Pediatric Hospital Medicine, UC San Diego-Rady Children's Hospital, San Diego (M.A.C.), the Department of Pediatrics, Divisions of Critical Care Medicine and Allergy, Immunology, and Bone Marrow Transplant, University of California, San Francisco, San Francisco (M.S.Z.), and the Division of Critical Care Medicine, UCSF Benioff Children's Hospital, Oakland (N.Z.C.) - all in California; the Department of Pediatrics, Baylor College of Medicine, Immunization Project, Texas Children's Hospital, Houston (J.A.B., L.C.S.); the Division of Critical Care Medicine, Department of Anesthesiology and Critical Care, Children's Hospital of Philadelphia, Philadelphia (K.C.); the Department of Pediatrics, Division of Infectious Diseases, University of Mississippi Medical Center, Jackson (C.V.H.); the Department of Pediatrics, Section of Critical Care Medicine, University of Colorado School of Medicine, and Children's Hospital Colorado, Aurora (A.B.M.); the Division of Critical Care Medicine, Department of Pediatrics, Northwestern University Feinberg School of Medicine, Ann and Robert H. Lurie Children's Hospital of Chicago, Chicago (B.M.C., K.N.M.); the Division of Pediatric Critical Care Medicine, Children's Hospital of Michigan, Central Michigan University, Detroit (S.M.H.), and the Division of Pediatric Critical Care Medicine, Department of Pediatrics, Mott Children's Hospital and University of Michigan, Ann Arbor (H.R.F.); the Section of Pediatric Critical Care, Department of Pediatrics, Arkansas Children's Hospital, Little Rock (K.I.); the Division of Pediatric Critical Care Medicine (E.H.M.), and the Department of Pediatrics (L.S.), Medical University of South Carolina, Charleston; the Department of Pediatrics, University of North Carolina at Chapel Hill Children's Hospital, Chapel Hill (S.P.S., T.C.W.); the Division of Pediatric Critical Care, Department of Pediatrics, Cooperman Barnabas Medical Center, Livingston, NJ (S.J.G.); the Division of Pediatric Infectious Diseases, Department of Pediatrics, Children's Mercy Kansas City, Kansas City, Missouri (J.E.S.); the Ryan White Center for Pediatric Infectious Disease and Global Health, Department of Pediatrics, Indiana University School of Medicine, Indianapolis (S.S.B.); the Department of Pediatrics, Division of Critical Care Medicine, University of Texas Southwestern, Children's Medical Center, Dallas (M.M.); the Division of Pediatric Critical Care, University of Minnesota Masonic Children's Hospital, Minneapolis (J.R.H.), and the Divisions of Pediatric Infectious Diseases and Pediatric Critical Care Medicine, Department of Pediatric and Adolescent Medicine, Mayo Clinic, Rochester (E.R.L.) - both in Minnesota; the Division of Pediatric Critical Care, Department of Pediatrics, University of Utah, Salt Lake City (H.C.); the Department of Pediatrics, Division of Cardiology, Louisiana State University Health Sciences Center and Children's Hospital of New Orleans, New Orleans (T.T.B.); the Division of Pediatric Critical Care, Department of Pediatrics, Children's Hospital and Medical Center, Omaha, NE (M.L.C.); and the Division of Pediatric Critical Care Medicine, Department of Pediatrics, University of Alabama at Birmingham, Birmingham (M.K.).; Zinter MS; From the Division of Pediatric Infectious Diseases, Department of Pediatrics, Vanderbilt University Medical Center, Nashville (N.B.H.); the Covid-19 Response Team, Centers for Disease Control and Prevention (S.M.O., A.M.P., S.M.G., K.N.P., A.P.C., M.M.P.), the Center for Childhood Infections and Vaccines of Children's Healthcare of Atlanta and the Department of Pediatrics, Emory University School of Medicine (S.K.), and the Division of Critical Care Medicine, Department of Pediatrics, Emory University School of Medicine, Children's Healthcare of Atlanta (K.M.T.) - all in Atlanta; the Department of Pediatrics, University of Cincinnati College of Medicine, Cincinnati Children's Hospital Medical Center, Cincinnati (M.A.S.), the Division of Pediatric Critical Care Medicine, Nationwide Children's Hospital, Columbus (K.E.B.), and the Division of Critical Care Medicine, Department of Pediatrics, Akron Children's Hospital, Akron (R.A.N.) - all in Ohio; the Department of Anesthesiology, Critical Care, and Pain Medicine, Boston Children's Hospital (M.M.N., A.G.R.), and the Departments of Anaesthesia and Pediatrics, Harvard Medical School (A.G.R.) - both in Boston; the Division of Infectious Diseases, Children's Hospital Los Angeles, and the Departments of Pediatrics and Molecular Microbiology and Immunology, University of Southern California, Los Angeles, Los Angeles (P.S.P.), the Division of Pediatric Hospital Medicine, UC San Diego-Rady Children's Hospital, San Diego (M.A.C.), the Department of Pediatrics, Divisions of Critical Care Medicine and Allergy, Immunology, and Bone Marrow Transplant, University of California, San Francisco, San Francisco (M.S.Z.), and the Division of Critical Care Medicine, UCSF Benioff Children's Hospital, Oakland (N.Z.C.) - all in California; the Department of Pediatrics, Baylor College of Medicine, Immunization Project, Texas Children's Hospital, Houston (J.A.B., L.C.S.); the Division of Critical Care Medicine, Department of Anesthesiology and Critical Care, Children's Hospital of Philadelphia, Philadelphia (K.C.); the Department of Pediatrics, Division of Infectious Diseases, University of Mississippi Medical Center, Jackson (C.V.H.); the Department of Pediatrics, Section of Critical Care Medicine, University of Colorado School of Medicine, and Children's Hospital Colorado, Aurora (A.B.M.); the Division of Critical Care Medicine, Department of Pediatrics, Northwestern University Feinberg School of Medicine, Ann and Robert H. Lurie Children's Hospital of Chicago, Chicago (B.M.C., K.N.M.); the Division of Pediatric Critical Care Medicine, Children's Hospital of Michigan, Central Michigan University, Detroit (S.M.H.), and the Division of Pediatric Critical Care Medicine, Department of Pediatrics, Mott Children's Hospital and University of Michigan, Ann Arbor (H.R.F.); the Section of Pediatric Critical Care, Department of Pediatrics, Arkansas Children's Hospital, Little Rock (K.I.); the Division of Pediatric Critical Care Medicine (E.H.M.), and the Department of Pediatrics (L.S.), Medical University of South Carolina, Charleston; the Department of Pediatrics, University of North Carolina at Chapel Hill Children's Hospital, Chapel Hill (S.P.S., T.C.W.); the Division of Pediatric Critical Care, Department of Pediatrics, Cooperman Barnabas Medical Center, Livingston, NJ (S.J.G.); the Division of Pediatric Infectious Diseases, Department of Pediatrics, Children's Mercy Kansas City, Kansas City, Missouri (J.E.S.); the Ryan White Center for Pediatric Infectious Disease and Global Health, Department of Pediatrics, Indiana University School of Medicine, Indianapolis (S.S.B.); the Department of Pediatrics, Division of Critical Care Medicine, University of Texas Southwestern, Children's Medical Center, Dallas (M.M.); the Division of Pediatric Critical Care, University of Minnesota Masonic Children's Hospital, Minneapolis (J.R.H.), and the Divisions of Pediatric Infectious Diseases and Pediatric Critical Care Medicine, Department of Pediatric and Adolescent Medicine, Mayo Clinic, Rochester (E.R.L.) - both in Minnesota; the Division of Pediatric Critical Care, Department of Pediatrics, University of Utah, Salt Lake City (H.C.); the Department of Pediatrics, Division of Cardiology, Louisiana State University Health Sciences Center and Children's Hospital of New Orleans, New Orleans (T.T.B.); the Division of Pediatric Critical Care, Department of Pediatrics, Children's Hospital and Medical Center, Omaha, NE (M.L.C.); and the Division of Pediatric Critical Care Medicine, Department of Pediatrics, University of Alabama at Birmingham, Birmingham (M.K.).; Bradford TT; From the Division of Pediatric Infectious Diseases, Department of Pediatrics, Vanderbilt University Medical Center, Nashville (N.B.H.); the Covid-19 Response Team, Centers for Disease Control and Prevention (S.M.O., A.M.P., S.M.G., K.N.P., A.P.C., M.M.P.), the Center for Childhood Infections and Vaccines of Children's Healthcare of Atlanta and the Department of Pediatrics, Emory University School of Medicine (S.K.), and the Division of Critical Care Medicine, Department of Pediatrics, Emory University School of Medicine, Children's Healthcare of Atlanta (K.M.T.) - all in Atlanta; the Department of Pediatrics, University of Cincinnati College of Medicine, Cincinnati Children's Hospital Medical Center, Cincinnati (M.A.S.), the Division of Pediatric Critical Care Medicine, Nationwide Children's Hospital, Columbus (K.E.B.), and the Division of Critical Care Medicine, Department of Pediatrics, Akron Children's Hospital, Akron (R.A.N.) - all in Ohio; the Department of Anesthesiology, Critical Care, and Pain Medicine, Boston Children's Hospital (M.M.N., A.G.R.), and the Departments of Anaesthesia and Pediatrics, Harvard Medical School (A.G.R.) - both in Boston; the Division of Infectious Diseases, Children's Hospital Los Angeles, and the Departments of Pediatrics and Molecular Microbiology and Immunology, University of Southern California, Los Angeles, Los Angeles (P.S.P.), the Division of Pediatric Hospital Medicine, UC San Diego-Rady Children's Hospital, San Diego (M.A.C.), the Department of Pediatrics, Divisions of Critical Care Medicine and Allergy, Immunology, and Bone Marrow Transplant, University of California, San Francisco, San Francisco (M.S.Z.), and the Division of Critical Care Medicine, UCSF Benioff Children's Hospital, Oakland (N.Z.C.) - all in California; the Department of Pediatrics, Baylor College of Medicine, Immunization Project, Texas Children's Hospital, Houston (J.A.B., L.C.S.); the Division of Critical Care Medicine, Department of Anesthesiology and Critical Care, Children's Hospital of Philadelphia, Philadelphia (K.C.); the Department of Pediatrics, Division of Infectious Diseases, University of Mississippi Medical Center, Jackson (C.V.H.); the Department of Pediatrics, Section of Critical Care Medicine, University of Colorado School of Medicine, and Children's Hospital Colorado, Aurora (A.B.M.); the Division of Critical Care Medicine, Department of Pediatrics, Northwestern University Feinberg School of Medicine, Ann and Robert H. Lurie Children's Hospital of Chicago, Chicago (B.M.C., K.N.M.); the Division of Pediatric Critical Care Medicine, Children's Hospital of Michigan, Central Michigan University, Detroit (S.M.H.), and the Division of Pediatric Critical Care Medicine, Department of Pediatrics, Mott Children's Hospital and University of Michigan, Ann Arbor (H.R.F.); the Section of Pediatric Critical Care, Department of Pediatrics, Arkansas Children's Hospital, Little Rock (K.I.); the Division of Pediatric Critical Care Medicine (E.H.M.), and the Department of Pediatrics (L.S.), Medical University of South Carolina, Charleston; the Department of Pediatrics, University of North Carolina at Chapel Hill Children's Hospital, Chapel Hill (S.P.S., T.C.W.); the Division of Pediatric Critical Care, Department of Pediatrics, Cooperman Barnabas Medical Center, Livingston, NJ (S.J.G.); the Division of Pediatric Infectious Diseases, Department of Pediatrics, Children's Mercy Kansas City, Kansas City, Missouri (J.E.S.); the Ryan White Center for Pediatric Infectious Disease and Global Health, Department of Pediatrics, Indiana University School of Medicine, Indianapolis (S.S.B.); the Department of Pediatrics, Division of Critical Care Medicine, University of Texas Southwestern, Children's Medical Center, Dallas (M.M.); the Division of Pediatric Critical Care, University of Minnesota Masonic Children's Hospital, Minneapolis (J.R.H.), and the Divisions of Pediatric Infectious Diseases and Pediatric Critical Care Medicine, Department of Pediatric and Adolescent Medicine, Mayo Clinic, Rochester (E.R.L.) - both in Minnesota; the Division of Pediatric Critical Care, Department of Pediatrics, University of Utah, Salt Lake City (H.C.); the Department of Pediatrics, Division of Cardiology, Louisiana State University Health Sciences Center and Children's Hospital of New Orleans, New Orleans (T.T.B.); the Division of Pediatric Critical Care, Department of Pediatrics, Children's Hospital and Medical Center, Omaha, NE (M.L.C.); and the Division of Pediatric Critical Care Medicine, Department of Pediatrics, University of Alabama at Birmingham, Birmingham (M.K.).; Flori HR; From the Division of Pediatric Infectious Diseases, Department of Pediatrics, Vanderbilt University Medical Center, Nashville (N.B.H.); the Covid-19 Response Team, Centers for Disease Control and Prevention (S.M.O., A.M.P., S.M.G., K.N.P., A.P.C., M.M.P.), the Center for Childhood Infections and Vaccines of Children's Healthcare of Atlanta and the Department of Pediatrics, Emory University School of Medicine (S.K.), and the Division of Critical Care Medicine, Department of Pediatrics, Emory University School of Medicine, Children's Healthcare of Atlanta (K.M.T.) - all in Atlanta; the Department of Pediatrics, University of Cincinnati College of Medicine, Cincinnati Children's Hospital Medical Center, Cincinnati (M.A.S.), the Division of Pediatric Critical Care Medicine, Nationwide Children's Hospital, Columbus (K.E.B.), and the Division of Critical Care Medicine, Department of Pediatrics, Akron Children's Hospital, Akron (R.A.N.) - all in Ohio; the Department of Anesthesiology, Critical Care, and Pain Medicine, Boston Children's Hospital (M.M.N., A.G.R.), and the Departments of Anaesthesia and Pediatrics, Harvard Medical School (A.G.R.) - both in Boston; the Division of Infectious Diseases, Children's Hospital Los Angeles, and the Departments of Pediatrics and Molecular Microbiology and Immunology, University of Southern California, Los Angeles, Los Angeles (P.S.P.), the Division of Pediatric Hospital Medicine, UC San Diego-Rady Children's Hospital, San Diego (M.A.C.), the Department of Pediatrics, Divisions of Critical Care Medicine and Allergy, Immunology, and Bone Marrow Transplant, University of California, San Francisco, San Francisco (M.S.Z.), and the Division of Critical Care Medicine, UCSF Benioff Children's Hospital, Oakland (N.Z.C.) - all in California; the Department of Pediatrics, Baylor College of Medicine, Immunization Project, Texas Children's Hospital, Houston (J.A.B., L.C.S.); the Division of Critical Care Medicine, Department of Anesthesiology and Critical Care, Children's Hospital of Philadelphia, Philadelphia (K.C.); the Department of Pediatrics, Division of Infectious Diseases, University of Mississippi Medical Center, Jackson (C.V.H.); the Department of Pediatrics, Section of Critical Care Medicine, University of Colorado School of Medicine, and Children's Hospital Colorado, Aurora (A.B.M.); the Division of Critical Care Medicine, Department of Pediatrics, Northwestern University Feinberg School of Medicine, Ann and Robert H. Lurie Children's Hospital of Chicago, Chicago (B.M.C., K.N.M.); the Division of Pediatric Critical Care Medicine, Children's Hospital of Michigan, Central Michigan University, Detroit (S.M.H.), and the Division of Pediatric Critical Care Medicine, Department of Pediatrics, Mott Children's Hospital and University of Michigan, Ann Arbor (H.R.F.); the Section of Pediatric Critical Care, Department of Pediatrics, Arkansas Children's Hospital, Little Rock (K.I.); the Division of Pediatric Critical Care Medicine (E.H.M.), and the Department of Pediatrics (L.S.), Medical University of South Carolina, Charleston; the Department of Pediatrics, University of North Carolina at Chapel Hill Children's Hospital, Chapel Hill (S.P.S., T.C.W.); the Division of Pediatric Critical Care, Department of Pediatrics, Cooperman Barnabas Medical Center, Livingston, NJ (S.J.G.); the Division of Pediatric Infectious Diseases, Department of Pediatrics, Children's Mercy Kansas City, Kansas City, Missouri (J.E.S.); the Ryan White Center for Pediatric Infectious Disease and Global Health, Department of Pediatrics, Indiana University School of Medicine, Indianapolis (S.S.B.); the Department of Pediatrics, Division of Critical Care Medicine, University of Texas Southwestern, Children's Medical Center, Dallas (M.M.); the Division of Pediatric Critical Care, University of Minnesota Masonic Children's Hospital, Minneapolis (J.R.H.), and the Divisions of Pediatric Infectious Diseases and Pediatric Critical Care Medicine, Department of Pediatric and Adolescent Medicine, Mayo Clinic, Rochester (E.R.L.) - both in Minnesota; the Division of Pediatric Critical Care, Department of Pediatrics, University of Utah, Salt Lake City (H.C.); the Department of Pediatrics, Division of Cardiology, Louisiana State University Health Sciences Center and Children's Hospital of New Orleans, New Orleans (T.T.B.); the Division of Pediatric Critical Care, Department of Pediatrics, Children's Hospital and Medical Center, Omaha, NE (M.L.C.); and the Division of Pediatric Critical Care Medicine, Department of Pediatrics, University of Alabama at Birmingham, Birmingham (M.K.).; Cullimore ML; From the Division of Pediatric Infectious Diseases, Department of Pediatrics, Vanderbilt University Medical Center, Nashville (N.B.H.); the Covid-19 Response Team, Centers for Disease Control and Prevention (S.M.O., A.M.P., S.M.G., K.N.P., A.P.C., M.M.P.), the Center for Childhood Infections and Vaccines of Children's Healthcare of Atlanta and the Department of Pediatrics, Emory University School of Medicine (S.K.), and the Division of Critical Care Medicine, Department of Pediatrics, Emory University School of Medicine, Children's Healthcare of Atlanta (K.M.T.) - all in Atlanta; the Department of Pediatrics, University of Cincinnati College of Medicine, Cincinnati Children's Hospital Medical Center, Cincinnati (M.A.S.), the Division of Pediatric Critical Care Medicine, Nationwide Children's Hospital, Columbus (K.E.B.), and the Division of Critical Care Medicine, Department of Pediatrics, Akron Children's Hospital, Akron (R.A.N.) - all in Ohio; the Department of Anesthesiology, Critical Care, and Pain Medicine, Boston Children's Hospital (M.M.N., A.G.R.), and the Departments of Anaesthesia and Pediatrics, Harvard Medical School (A.G.R.) - both in Boston; the Division of Infectious Diseases, Children's Hospital Los Angeles, and the Departments of Pediatrics and Molecular Microbiology and Immunology, University of Southern California, Los Angeles, Los Angeles (P.S.P.), the Division of Pediatric Hospital Medicine, UC San Diego-Rady Children's Hospital, San Diego (M.A.C.), the Department of Pediatrics, Divisions of Critical Care Medicine and Allergy, Immunology, and Bone Marrow Transplant, University of California, San Francisco, San Francisco (M.S.Z.), and the Division of Critical Care Medicine, UCSF Benioff Children's Hospital, Oakland (N.Z.C.) - all in California; the Department of Pediatrics, Baylor College of Medicine, Immunization Project, Texas Children's Hospital, Houston (J.A.B., L.C.S.); the Division of Critical Care Medicine, Department of Anesthesiology and Critical Care, Children's Hospital of Philadelphia, Philadelphia (K.C.); the Department of Pediatrics, Division of Infectious Diseases, University of Mississippi Medical Center, Jackson (C.V.H.); the Department of Pediatrics, Section of Critical Care Medicine, University of Colorado School of Medicine, and Children's Hospital Colorado, Aurora (A.B.M.); the Division of Critical Care Medicine, Department of Pediatrics, Northwestern University Feinberg School of Medicine, Ann and Robert H. Lurie Children's Hospital of Chicago, Chicago (B.M.C., K.N.M.); the Division of Pediatric Critical Care Medicine, Children's Hospital of Michigan, Central Michigan University, Detroit (S.M.H.), and the Division of Pediatric Critical Care Medicine, Department of Pediatrics, Mott Children's Hospital and University of Michigan, Ann Arbor (H.R.F.); the Section of Pediatric Critical Care, Department of Pediatrics, Arkansas Children's Hospital, Little Rock (K.I.); the Division of Pediatric Critical Care Medicine (E.H.M.), and the Department of Pediatrics (L.S.), Medical University of South Carolina, Charleston; the Department of Pediatrics, University of North Carolina at Chapel Hill Children's Hospital, Chapel Hill (S.P.S., T.C.W.); the Division of Pediatric Critical Care, Department of Pediatrics, Cooperman Barnabas Medical Center, Livingston, NJ (S.J.G.); the Division of Pediatric Infectious Diseases, Department of Pediatrics, Children's Mercy Kansas City, Kansas City, Missouri (J.E.S.); the Ryan White Center for Pediatric Infectious Disease and Global Health, Department of Pediatrics, Indiana University School of Medicine, Indianapolis (S.S.B.); the Department of Pediatrics, Division of Critical Care Medicine, University of Texas Southwestern, Children's Medical Center, Dallas (M.M.); the Division of Pediatric Critical Care, University of Minnesota Masonic Children's Hospital, Minneapolis (J.R.H.), and the Divisions of Pediatric Infectious Diseases and Pediatric Critical Care Medicine, Department of Pediatric and Adolescent Medicine, Mayo Clinic, Rochester (E.R.L.) - both in Minnesota; the Division of Pediatric Critical Care, Department of Pediatrics, University of Utah, Salt Lake City (H.C.); the Department of Pediatrics, Division of Cardiology, Louisiana State University Health Sciences Center and Children's Hospital of New Orleans, New Orleans (T.T.B.); the Division of Pediatric Critical Care, Department of Pediatrics, Children's Hospital and Medical Center, Omaha, NE (M.L.C.); and the Division of Pediatric Critical Care Medicine, Department of Pediatrics, University of Alabama at Birmingham, Birmingham (M.K.).; Kong M; From the Division of Pediatric Infectious Diseases, Department of Pediatrics, Vanderbilt University Medical Center, Nashville (N.B.H.); the Covid-19 Response Team, Centers for Disease Control and Prevention (S.M.O., A.M.P., S.M.G., K.N.P., A.P.C., M.M.P.), the Center for Childhood Infections and Vaccines of Children's Healthcare of Atlanta and the Department of Pediatrics, Emory University School of Medicine (S.K.), and the Division of Critical Care Medicine, Department of Pediatrics, Emory University School of Medicine, Children's Healthcare of Atlanta (K.M.T.) - all in Atlanta; the Department of Pediatrics, University of Cincinnati College of Medicine, Cincinnati Children's Hospital Medical Center, Cincinnati (M.A.S.), the Division of Pediatric Critical Care Medicine, Nationwide Children's Hospital, Columbus (K.E.B.), and the Division of Critical Care Medicine, Department of Pediatrics, Akron Children's Hospital, Akron (R.A.N.) - all in Ohio; the Department of Anesthesiology, Critical Care, and Pain Medicine, Boston Children's Hospital (M.M.N., A.G.R.), and the Departments of Anaesthesia and Pediatrics, Harvard Medical School (A.G.R.) - both in Boston; the Division of Infectious Diseases, Children's Hospital Los Angeles, and the Departments of Pediatrics and Molecular Microbiology and Immunology, University of Southern California, Los Angeles, Los Angeles (P.S.P.), the Division of Pediatric Hospital Medicine, UC San Diego-Rady Children's Hospital, San Diego (M.A.C.), the Department of Pediatrics, Divisions of Critical Care Medicine and Allergy, Immunology, and Bone Marrow Transplant, University of California, San Francisco, San Francisco (M.S.Z.), and the Division of Critical Care Medicine, UCSF Benioff Children's Hospital, Oakland (N.Z.C.) - all in California; the Department of Pediatrics, Baylor College of Medicine, Immunization Project, Texas Children's Hospital, Houston (J.A.B., L.C.S.); the Division of Critical Care Medicine, Department of Anesthesiology and Critical Care, Children's Hospital of Philadelphia, Philadelphia (K.C.); the Department of Pediatrics, Division of Infectious Diseases, University of Mississippi Medical Center, Jackson (C.V.H.); the Department of Pediatrics, Section of Critical Care Medicine, University of Colorado School of Medicine, and Children's Hospital Colorado, Aurora (A.B.M.); the Division of Critical Care Medicine, Department of Pediatrics, Northwestern University Feinberg School of Medicine, Ann and Robert H. Lurie Children's Hospital of Chicago, Chicago (B.M.C., K.N.M.); the Division of Pediatric Critical Care Medicine, Children's Hospital of Michigan, Central Michigan University, Detroit (S.M.H.), and the Division of Pediatric Critical Care Medicine, Department of Pediatrics, Mott Children's Hospital and University of Michigan, Ann Arbor (H.R.F.); the Section of Pediatric Critical Care, Department of Pediatrics, Arkansas Children's Hospital, Little Rock (K.I.); the Division of Pediatric Critical Care Medicine (E.H.M.), and the Department of Pediatrics (L.S.), Medical University of South Carolina, Charleston; the Department of Pediatrics, University of North Carolina at Chapel Hill Children's Hospital, Chapel Hill (S.P.S., T.C.W.); the Division of Pediatric Critical Care, Department of Pediatrics, Cooperman Barnabas Medical Center, Livingston, NJ (S.J.G.); the Division of Pediatric Infectious Diseases, Department of Pediatrics, Children's Mercy Kansas City, Kansas City, Missouri (J.E.S.); the Ryan White Center for Pediatric Infectious Disease and Global Health, Department of Pediatrics, Indiana University School of Medicine, Indianapolis (S.S.B.); the Department of Pediatrics, Division of Critical Care Medicine, University of Texas Southwestern, Children's Medical Center, Dallas (M.M.); the Division of Pediatric Critical Care, University of Minnesota Masonic Children's Hospital, Minneapolis (J.R.H.), and the Divisions of Pediatric Infectious Diseases and Pediatric Critical Care Medicine, Department of Pediatric and Adolescent Medicine, Mayo Clinic, Rochester (E.R.L.) - both in Minnesota; the Division of Pediatric Critical Care, Department of Pediatrics, University of Utah, Salt Lake City (H.C.); the Department of Pediatrics, Division of Cardiology, Louisiana State University Health Sciences Center and Children's Hospital of New Orleans, New Orleans (T.T.B.); the Division of Pediatric Critical Care, Department of Pediatrics, Children's Hospital and Medical Center, Omaha, NE (M.L.C.); and the Division of Pediatric Critical Care Medicine, Department of Pediatrics, University of Alabama at Birmingham, Birmingham (M.K.).; Cvijanovich NZ; From the Division of Pediatric Infectious Diseases, Department of Pediatrics, Vanderbilt University Medical Center, Nashville (N.B.H.); the Covid-19 Response Team, Centers for Disease Control and Prevention (S.M.O., A.M.P., S.M.G., K.N.P., A.P.C., M.M.P.), the Center for Childhood Infections and Vaccines of Children's Healthcare of Atlanta and the Department of Pediatrics, Emory University School of Medicine (S.K.), and the Division of Critical Care Medicine, Department of Pediatrics, Emory University School of Medicine, Children's Healthcare of Atlanta (K.M.T.) - all in Atlanta; the Department of Pediatrics, University of Cincinnati College of Medicine, Cincinnati Children's Hospital Medical Center, Cincinnati (M.A.S.), the Division of Pediatric Critical Care Medicine, Nationwide Children's Hospital, Columbus (K.E.B.), and the Division of Critical Care Medicine, Department of Pediatrics, Akron Children's Hospital, Akron (R.A.N.) - all in Ohio; the Department of Anesthesiology, Critical Care, and Pain Medicine, Boston Children's Hospital (M.M.N., A.G.R.), and the Departments of Anaesthesia and Pediatrics, Harvard Medical School (A.G.R.) - both in Boston; the Division of Infectious Diseases, Children's Hospital Los Angeles, and the Departments of Pediatrics and Molecular Microbiology and Immunology, University of Southern California, Los Angeles, Los Angeles (P.S.P.), the Division of Pediatric Hospital Medicine, UC San Diego-Rady Children's Hospital, San Diego (M.A.C.), the Department of Pediatrics, Divisions of Critical Care Medicine and Allergy, Immunology, and Bone Marrow Transplant, University of California, San Francisco, San Francisco (M.S.Z.), and the Division of Critical Care Medicine, UCSF Benioff Children's Hospital, Oakland (N.Z.C.) - all in California; the Department of Pediatrics, Baylor College of Medicine, Immunization Project, Texas Children's Hospital, Houston (J.A.B., L.C.S.); the Division of Critical Care Medicine, Department of Anesthesiology and Critical Care, Children's Hospital of Philadelphia, Philadelphia (K.C.); the Department of Pediatrics, Division of Infectious Diseases, University of Mississippi Medical Center, Jackson (C.V.H.); the Department of Pediatrics, Section of Critical Care Medicine, University of Colorado School of Medicine, and Children's Hospital Colorado, Aurora (A.B.M.); the Division of Critical Care Medicine, Department of Pediatrics, Northwestern University Feinberg School of Medicine, Ann and Robert H. Lurie Children's Hospital of Chicago, Chicago (B.M.C., K.N.M.); the Division of Pediatric Critical Care Medicine, Children's Hospital of Michigan, Central Michigan University, Detroit (S.M.H.), and the Division of Pediatric Critical Care Medicine, Department of Pediatrics, Mott Children's Hospital and University of Michigan, Ann Arbor (H.R.F.); the Section of Pediatric Critical Care, Department of Pediatrics, Arkansas Children's Hospital, Little Rock (K.I.); the Division of Pediatric Critical Care Medicine (E.H.M.), and the Department of Pediatrics (L.S.), Medical University of South Carolina, Charleston; the Department of Pediatrics, University of North Carolina at Chapel Hill Children's Hospital, Chapel Hill (S.P.S., T.C.W.); the Division of Pediatric Critical Care, Department of Pediatrics, Cooperman Barnabas Medical Center, Livingston, NJ (S.J.G.); the Division of Pediatric Infectious Diseases, Department of Pediatrics, Children's Mercy Kansas City, Kansas City, Missouri (J.E.S.); the Ryan White Center for Pediatric Infectious Disease and Global Health, Department of Pediatrics, Indiana University School of Medicine, Indianapolis (S.S.B.); the Department of Pediatrics, Division of Critical Care Medicine, University of Texas Southwestern, Children's Medical Center, Dallas (M.M.); the Division of Pediatric Critical Care, University of Minnesota Masonic Children's Hospital, Minneapolis (J.R.H.), and the Divisions of Pediatric Infectious Diseases and Pediatric Critical Care Medicine, Department of Pediatric and Adolescent Medicine, Mayo Clinic, Rochester (E.R.L.) - both in Minnesota; the Division of Pediatric Critical Care, Department of Pediatrics, University of Utah, Salt Lake City (H.C.); the Department of Pediatrics, Division of Cardiology, Louisiana State University Health Sciences Center and Children's Hospital of New Orleans, New Orleans (T.T.B.); the Division of Pediatric Critical Care, Department of Pediatrics, Children's Hospital and Medical Center, Omaha, NE (M.L.C.); and the Division of Pediatric Critical Care Medicine, Department of Pediatrics, University of Alabama at Birmingham, Birmingham (M.K.).; Gilboa SM; From the Division of Pediatric Infectious Diseases, Department of Pediatrics, Vanderbilt University Medical Center, Nashville (N.B.H.); the Covid-19 Response Team, Centers for Disease Control and Prevention (S.M.O., A.M.P., S.M.G., K.N.P., A.P.C., M.M.P.), the Center for Childhood Infections and Vaccines of Children's Healthcare of Atlanta and the Department of Pediatrics, Emory University School of Medicine (S.K.), and the Division of Critical Care Medicine, Department of Pediatrics, Emory University School of Medicine, Children's Healthcare of Atlanta (K.M.T.) - all in Atlanta; the Department of Pediatrics, University of Cincinnati College of Medicine, Cincinnati Children's Hospital Medical Center, Cincinnati (M.A.S.), the Division of Pediatric Critical Care Medicine, Nationwide Children's Hospital, Columbus (K.E.B.), and the Division of Critical Care Medicine, Department of Pediatrics, Akron Children's Hospital, Akron (R.A.N.) - all in Ohio; the Department of Anesthesiology, Critical Care, and Pain Medicine, Boston Children's Hospital (M.M.N., A.G.R.), and the Departments of Anaesthesia and Pediatrics, Harvard Medical School (A.G.R.) - both in Boston; the Division of Infectious Diseases, Children's Hospital Los Angeles, and the Departments of Pediatrics and Molecular Microbiology and Immunology, University of Southern California, Los Angeles, Los Angeles (P.S.P.), the Division of Pediatric Hospital Medicine, UC San Diego-Rady Children's Hospital, San Diego (M.A.C.), the Department of Pediatrics, Divisions of Critical Care Medicine and Allergy, Immunology, and Bone Marrow Transplant, University of California, San Francisco, San Francisco (M.S.Z.), and the Division of Critical Care Medicine, UCSF Benioff Children's Hospital, Oakland (N.Z.C.) - all in California; the Department of Pediatrics, Baylor College of Medicine, Immunization Project, Texas Children's Hospital, Houston (J.A.B., L.C.S.); the Division of Critical Care Medicine, Department of Anesthesiology and Critical Care, Children's Hospital of Philadelphia, Philadelphia (K.C.); the Department of Pediatrics, Division of Infectious Diseases, University of Mississippi Medical Center, Jackson (C.V.H.); the Department of Pediatrics, Section of Critical Care Medicine, University of Colorado School of Medicine, and Children's Hospital Colorado, Aurora (A.B.M.); the Division of Critical Care Medicine, Department of Pediatrics, Northwestern University Feinberg School of Medicine, Ann and Robert H. Lurie Children's Hospital of Chicago, Chicago (B.M.C., K.N.M.); the Division of Pediatric Critical Care Medicine, Children's Hospital of Michigan, Central Michigan University, Detroit (S.M.H.), and the Division of Pediatric Critical Care Medicine, Department of Pediatrics, Mott Children's Hospital and University of Michigan, Ann Arbor (H.R.F.); the Section of Pediatric Critical Care, Department of Pediatrics, Arkansas Children's Hospital, Little Rock (K.I.); the Division of Pediatric Critical Care Medicine (E.H.M.), and the Department of Pediatrics (L.S.), Medical University of South Carolina, Charleston; the Department of Pediatrics, University of North Carolina at Chapel Hill Children's Hospital, Chapel Hill (S.P.S., T.C.W.); the Division of Pediatric Critical Care, Department of Pediatrics, Cooperman Barnabas Medical Center, Livingston, NJ (S.J.G.); the Division of Pediatric Infectious Diseases, Department of Pediatrics, Children's Mercy Kansas City, Kansas City, Missouri (J.E.S.); the Ryan White Center for Pediatric Infectious Disease and Global Health, Department of Pediatrics, Indiana University School of Medicine, Indianapolis (S.S.B.); the Department of Pediatrics, Division of Critical Care Medicine, University of Texas Southwestern, Children's Medical Center, Dallas (M.M.); the Division of Pediatric Critical Care, University of Minnesota Masonic Children's Hospital, Minneapolis (J.R.H.), and the Divisions of Pediatric Infectious Diseases and Pediatric Critical Care Medicine, Department of Pediatric and Adolescent Medicine, Mayo Clinic, Rochester (E.R.L.) - both in Minnesota; the Division of Pediatric Critical Care, Department of Pediatrics, University of Utah, Salt Lake City (H.C.); the Department of Pediatrics, Division of Cardiology, Louisiana State University Health Sciences Center and Children's Hospital of New Orleans, New Orleans (T.T.B.); the Division of Pediatric Critical Care, Department of Pediatrics, Children's Hospital and Medical Center, Omaha, NE (M.L.C.); and the Division of Pediatric Critical Care Medicine, Department of Pediatrics, University of Alabama at Birmingham, Birmingham (M.K.).; Polen KN; From the Division of Pediatric Infectious Diseases, Department of Pediatrics, Vanderbilt University Medical Center, Nashville (N.B.H.); the Covid-19 Response Team, Centers for Disease Control and Prevention (S.M.O., A.M.P., S.M.G., K.N.P., A.P.C., M.M.P.), the Center for Childhood Infections and Vaccines of Children's Healthcare of Atlanta and the Department of Pediatrics, Emory University School of Medicine (S.K.), and the Division of Critical Care Medicine, Department of Pediatrics, Emory University School of Medicine, Children's Healthcare of Atlanta (K.M.T.) - all in Atlanta; the Department of Pediatrics, University of Cincinnati College of Medicine, Cincinnati Children's Hospital Medical Center, Cincinnati (M.A.S.), the Division of Pediatric Critical Care Medicine, Nationwide Children's Hospital, Columbus (K.E.B.), and the Division of Critical Care Medicine, Department of Pediatrics, Akron Children's Hospital, Akron (R.A.N.) - all in Ohio; the Department of Anesthesiology, Critical Care, and Pain Medicine, Boston Children's Hospital (M.M.N., A.G.R.), and the Departments of Anaesthesia and Pediatrics, Harvard Medical School (A.G.R.) - both in Boston; the Division of Infectious Diseases, Children's Hospital Los Angeles, and the Departments of Pediatrics and Molecular Microbiology and Immunology, University of Southern California, Los Angeles, Los Angeles (P.S.P.), the Division of Pediatric Hospital Medicine, UC San Diego-Rady Children's Hospital, San Diego (M.A.C.), the Department of Pediatrics, Divisions of Critical Care Medicine and Allergy, Immunology, and Bone Marrow Transplant, University of California, San Francisco, San Francisco (M.S.Z.), and the Division of Critical Care Medicine, UCSF Benioff Children's Hospital, Oakland (N.Z.C.) - all in California; the Department of Pediatrics, Baylor College of Medicine, Immunization Project, Texas Children's Hospital, Houston (J.A.B., L.C.S.); the Division of Critical Care Medicine, Department of Anesthesiology and Critical Care, Children's Hospital of Philadelphia, Philadelphia (K.C.); the Department of Pediatrics, Division of Infectious Diseases, University of Mississippi Medical Center, Jackson (C.V.H.); the Department of Pediatrics, Section of Critical Care Medicine, University of Colorado School of Medicine, and Children's Hospital Colorado, Aurora (A.B.M.); the Division of Critical Care Medicine, Department of Pediatrics, Northwestern University Feinberg School of Medicine, Ann and Robert H. Lurie Children's Hospital of Chicago, Chicago (B.M.C., K.N.M.); the Division of Pediatric Critical Care Medicine, Children's Hospital of Michigan, Central Michigan University, Detroit (S.M.H.), and the Division of Pediatric Critical Care Medicine, Department of Pediatrics, Mott Children's Hospital and University of Michigan, Ann Arbor (H.R.F.); the Section of Pediatric Critical Care, Department of Pediatrics, Arkansas Children's Hospital, Little Rock (K.I.); the Division of Pediatric Critical Care Medicine (E.H.M.), and the Department of Pediatrics (L.S.), Medical University of South Carolina, Charleston; the Department of Pediatrics, University of North Carolina at Chapel Hill Children's Hospital, Chapel Hill (S.P.S., T.C.W.); the Division of Pediatric Critical Care, Department of Pediatrics, Cooperman Barnabas Medical Center, Livingston, NJ (S.J.G.); the Division of Pediatric Infectious Diseases, Department of Pediatrics, Children's Mercy Kansas City, Kansas City, Missouri (J.E.S.); the Ryan White Center for Pediatric Infectious Disease and Global Health, Department of Pediatrics, Indiana University School of Medicine, Indianapolis (S.S.B.); the Department of Pediatrics, Division of Critical Care Medicine, University of Texas Southwestern, Children's Medical Center, Dallas (M.M.); the Division of Pediatric Critical Care, University of Minnesota Masonic Children's Hospital, Minneapolis (J.R.H.), and the Divisions of Pediatric Infectious Diseases and Pediatric Critical Care Medicine, Department of Pediatric and Adolescent Medicine, Mayo Clinic, Rochester (E.R.L.) - both in Minnesota; the Division of Pediatric Critical Care, Department of Pediatrics, University of Utah, Salt Lake City (H.C.); the Department of Pediatrics, Division of Cardiology, Louisiana State University Health Sciences Center and Children's Hospital of New Orleans, New Orleans (T.T.B.); the Division of Pediatric Critical Care, Department of Pediatrics, Children's Hospital and Medical Center, Omaha, NE (M.L.C.); and the Division of Pediatric Critical Care Medicine, Department of Pediatrics, University of Alabama at Birmingham, Birmingham (M.K.).; Campbell AP; From the Division of Pediatric Infectious Diseases, Department of Pediatrics, Vanderbilt University Medical Center, Nashville (N.B.H.); the Covid-19 Response Team, Centers for Disease Control and Prevention (S.M.O., A.M.P., S.M.G., K.N.P., A.P.C., M.M.P.), the Center for Childhood Infections and Vaccines of Children's Healthcare of Atlanta and the Department of Pediatrics, Emory University School of Medicine (S.K.), and the Division of Critical Care Medicine, Department of Pediatrics, Emory University School of Medicine, Children's Healthcare of Atlanta (K.M.T.) - all in Atlanta; the Department of Pediatrics, University of Cincinnati College of Medicine, Cincinnati Children's Hospital Medical Center, Cincinnati (M.A.S.), the Division of Pediatric Critical Care Medicine, Nationwide Children's Hospital, Columbus (K.E.B.), and the Division of Critical Care Medicine, Department of Pediatrics, Akron Children's Hospital, Akron (R.A.N.) - all in Ohio; the Department of Anesthesiology, Critical Care, and Pain Medicine, Boston Children's Hospital (M.M.N., A.G.R.), and the Departments of Anaesthesia and Pediatrics, Harvard Medical School (A.G.R.) - both in Boston; the Division of Infectious Diseases, Children's Hospital Los Angeles, and the Departments of Pediatrics and Molecular Microbiology and Immunology, University of Southern California, Los Angeles, Los Angeles (P.S.P.), the Division of Pediatric Hospital Medicine, UC San Diego-Rady Children's Hospital, San Diego (M.A.C.), the Department of Pediatrics, Divisions of Critical Care Medicine and Allergy, Immunology, and Bone Marrow Transplant, University of California, San Francisco, San Francisco (M.S.Z.), and the Division of Critical Care Medicine, UCSF Benioff Children's Hospital, Oakland (N.Z.C.) - all in California; the Department of Pediatrics, Baylor College of Medicine, Immunization Project, Texas Children's Hospital, Houston (J.A.B., L.C.S.); the Division of Critical Care Medicine, Department of Anesthesiology and Critical Care, Children's Hospital of Philadelphia, Philadelphia (K.C.); the Department of Pediatrics, Division of Infectious Diseases, University of Mississippi Medical Center, Jackson (C.V.H.); the Department of Pediatrics, Section of Critical Care Medicine, University of Colorado School of Medicine, and Children's Hospital Colorado, Aurora (A.B.M.); the Division of Critical Care Medicine, Department of Pediatrics, Northwestern University Feinberg School of Medicine, Ann and Robert H. Lurie Children's Hospital of Chicago, Chicago (B.M.C., K.N.M.); the Division of Pediatric Critical Care Medicine, Children's Hospital of Michigan, Central Michigan University, Detroit (S.M.H.), and the Division of Pediatric Critical Care Medicine, Department of Pediatrics, Mott Children's Hospital and University of Michigan, Ann Arbor (H.R.F.); the Section of Pediatric Critical Care, Department of Pediatrics, Arkansas Children's Hospital, Little Rock (K.I.); the Division of Pediatric Critical Care Medicine (E.H.M.), and the Department of Pediatrics (L.S.), Medical University of South Carolina, Charleston; the Department of Pediatrics, University of North Carolina at Chapel Hill Children's Hospital, Chapel Hill (S.P.S., T.C.W.); the Division of Pediatric Critical Care, Department of Pediatrics, Cooperman Barnabas Medical Center, Livingston, NJ (S.J.G.); the Division of Pediatric Infectious Diseases, Department of Pediatrics, Children's Mercy Kansas City, Kansas City, Missouri (J.E.S.); the Ryan White Center for Pediatric Infectious Disease and Global Health, Department of Pediatrics, Indiana University School of Medicine, Indianapolis (S.S.B.); the Department of Pediatrics, Division of Critical Care Medicine, University of Texas Southwestern, Children's Medical Center, Dallas (M.M.); the Division of Pediatric Critical Care, University of Minnesota Masonic Children's Hospital, Minneapolis (J.R.H.), and the Divisions of Pediatric Infectious Diseases and Pediatric Critical Care Medicine, Department of Pediatric and Adolescent Medicine, Mayo Clinic, Rochester (E.R.L.) - both in Minnesota; the Division of Pediatric Critical Care, Department of Pediatrics, University of Utah, Salt Lake City (H.C.); the Department of Pediatrics, Division of Cardiology, Louisiana State University Health Sciences Center and Children's Hospital of New Orleans, New Orleans (T.T.B.); the Division of Pediatric Critical Care, Department of Pediatrics, Children's Hospital and Medical Center, Omaha, NE (M.L.C.); and the Division of Pediatric Critical Care Medicine, Department of Pediatrics, University of Alabama at Birmingham, Birmingham (M.K.).; Randolph AG; From the Division of Pediatric Infectious Diseases, Department of Pediatrics, Vanderbilt University Medical Center, Nashville (N.B.H.); the Covid-19 Response Team, Centers for Disease Control and Prevention (S.M.O., A.M.P., S.M.G., K.N.P., A.P.C., M.M.P.), the Center for Childhood Infections and Vaccines of Children's Healthcare of Atlanta and the Department of Pediatrics, Emory University School of Medicine (S.K.), and the Division of Critical Care Medicine, Department of Pediatrics, Emory University School of Medicine, Children's Healthcare of Atlanta (K.M.T.) - all in Atlanta; the Department of Pediatrics, University of Cincinnati College of Medicine, Cincinnati Children's Hospital Medical Center, Cincinnati (M.A.S.), the Division of Pediatric Critical Care Medicine, Nationwide Children's Hospital, Columbus (K.E.B.), and the Division of Critical Care Medicine, Department of Pediatrics, Akron Children's Hospital, Akron (R.A.N.) - all in Ohio; the Department of Anesthesiology, Critical Care, and Pain Medicine, Boston Children's Hospital (M.M.N., A.G.R.), and the Departments of Anaesthesia and Pediatrics, Harvard Medical School (A.G.R.) - both in Boston; the Division of Infectious Diseases, Children's Hospital Los Angeles, and the Departments of Pediatrics and Molecular Microbiology and Immunology, University of Southern California, Los Angeles, Los Angeles (P.S.P.), the Division of Pediatric Hospital Medicine, UC San Diego-Rady Children's Hospital, San Diego (M.A.C.), the Department of Pediatrics, Divisions of Critical Care Medicine and Allergy, Immunology, and Bone Marrow Transplant, University of California, San Francisco, San Francisco (M.S.Z.), and the Division of Critical Care Medicine, UCSF Benioff Children's Hospital, Oakland (N.Z.C.) - all in California; the Department of Pediatrics, Baylor College of Medicine, Immunization Project, Texas Children's Hospital, Houston (J.A.B., L.C.S.); the Division of Critical Care Medicine, Department of Anesthesiology and Critical Care, Children's Hospital of Philadelphia, Philadelphia (K.C.); the Department of Pediatrics, Division of Infectious Diseases, University of Mississippi Medical Center, Jackson (C.V.H.); the Department of Pediatrics, Section of Critical Care Medicine, University of Colorado School of Medicine, and Children's Hospital Colorado, Aurora (A.B.M.); the Division of Critical Care Medicine, Department of Pediatrics, Northwestern University Feinberg School of Medicine, Ann and Robert H. Lurie Children's Hospital of Chicago, Chicago (B.M.C., K.N.M.); the Division of Pediatric Critical Care Medicine, Children's Hospital of Michigan, Central Michigan University, Detroit (S.M.H.), and the Division of Pediatric Critical Care Medicine, Department of Pediatrics, Mott Children's Hospital and University of Michigan, Ann Arbor (H.R.F.); the Section of Pediatric Critical Care, Department of Pediatrics, Arkansas Children's Hospital, Little Rock (K.I.); the Division of Pediatric Critical Care Medicine (E.H.M.), and the Department of Pediatrics (L.S.), Medical University of South Carolina, Charleston; the Department of Pediatrics, University of North Carolina at Chapel Hill Children's Hospital, Chapel Hill (S.P.S., T.C.W.); the Division of Pediatric Critical Care, Department of Pediatrics, Cooperman Barnabas Medical Center, Livingston, NJ (S.J.G.); the Division of Pediatric Infectious Diseases, Department of Pediatrics, Children's Mercy Kansas City, Kansas City, Missouri (J.E.S.); the Ryan White Center for Pediatric Infectious Disease and Global Health, Department of Pediatrics, Indiana University School of Medicine, Indianapolis (S.S.B.); the Department of Pediatrics, Division of Critical Care Medicine, University of Texas Southwestern, Children's Medical Center, Dallas (M.M.); the Division of Pediatric Critical Care, University of Minnesota Masonic Children's Hospital, Minneapolis (J.R.H.), and the Divisions of Pediatric Infectious Diseases and Pediatric Critical Care Medicine, Department of Pediatric and Adolescent Medicine, Mayo Clinic, Rochester (E.R.L.) - both in Minnesota; the Division of Pediatric Critical Care, Department of Pediatrics, University of Utah, Salt Lake City (H.C.); the Department of Pediatrics, Division of Cardiology, Louisiana State University Health Sciences Center and Children's Hospital of New Orleans, New Orleans (T.T.B.); the Division of Pediatric Critical Care, Department of Pediatrics, Children's Hospital and Medical Center, Omaha, NE (M.L.C.); and the Division of Pediatric Critical Care Medicine, Department of Pediatrics, University of Alabama at Birmingham, Birmingham (M.K.).; Patel MM; From the Division of Pediatric Infectious Diseases, Department of Pediatrics, Vanderbilt University Medical Center, Nashville (N.B.H.); the Covid-19 Response Team, Centers for Disease Control and Prevention (S.M.O., A.M.P., S.M.G., K.N.P., A.P.C., M.M.P.), the Center for Childhood Infections and Vaccines of Children's Healthcare of Atlanta and the Department of Pediatrics, Emory University School of Medicine (S.K.), and the Division of Critical Care Medicine, Department of Pediatrics, Emory University School of Medicine, Children's Healthcare of Atlanta (K.M.T.) - all in Atlanta; the Department of Pediatrics, University of Cincinnati College of Medicine, Cincinnati Children's Hospital Medical Center, Cincinnati (M.A.S.), the Division of Pediatric Critical Care Medicine, Nationwide Children's Hospital, Columbus (K.E.B.), and the Division of Critical Care Medicine, Department of Pediatrics, Akron Children's Hospital, Akron (R.A.N.) - all in Ohio; the Department of Anesthesiology, Critical Care, and Pain Medicine, Boston Children's Hospital (M.M.N., A.G.R.), and the Departments of Anaesthesia and Pediatrics, Harvard Medical School (A.G.R.) - both in Boston; the Division of Infectious Diseases, Children's Hospital Los Angeles, and the Departments of Pediatrics and Molecular Microbiology and Immunology, University of Southern California, Los Angeles, Los Angeles (P.S.P.), the Division of Pediatric Hospital Medicine, UC San Diego-Rady Children's Hospital, San Diego (M.A.C.), the Department of Pediatrics, Divisions of Critical Care Medicine and Allergy, Immunology, and Bone Marrow Transplant, University of California, San Francisco, San Francisco (M.S.Z.), and the Division of Critical Care Medicine, UCSF Benioff Children's Hospital, Oakland (N.Z.C.) - all in California; the Department of Pediatrics, Baylor College of Medicine, Immunization Project, Texas Children's Hospital, Houston (J.A.B., L.C.S.); the Division of Critical Care Medicine, Department of Anesthesiology and Critical Care, Children's Hospital of Philadelphia, Philadelphia (K.C.); the Department of Pediatrics, Division of Infectious Diseases, University of Mississippi Medical Center, Jackson (C.V.H.); the Department of Pediatrics, Section of Critical Care Medicine, University of Colorado School of Medicine, and Children's Hospital Colorado, Aurora (A.B.M.); the Division of Critical Care Medicine, Department of Pediatrics, Northwestern University Feinberg School of Medicine, Ann and Robert H. Lurie Children's Hospital of Chicago, Chicago (B.M.C., K.N.M.); the Division of Pediatric Critical Care Medicine, Children's Hospital of Michigan, Central Michigan University, Detroit (S.M.H.), and the Division of Pediatric Critical Care Medicine, Department of Pediatrics, Mott Children's Hospital and University of Michigan, Ann Arbor (H.R.F.); the Section of Pediatric Critical Care, Department of Pediatrics, Arkansas Children's Hospital, Little Rock (K.I.); the Division of Pediatric Critical Care Medicine (E.H.M.), and the Department of Pediatrics (L.S.), Medical University of South Carolina, Charleston; the Department of Pediatrics, University of North Carolina at Chapel Hill Children's Hospital, Chapel Hill (S.P.S., T.C.W.); the Division of Pediatric Critical Care, Department of Pediatrics, Cooperman Barnabas Medical Center, Livingston, NJ (S.J.G.); the Division of Pediatric Infectious Diseases, Department of Pediatrics, Children's Mercy Kansas City, Kansas City, Missouri (J.E.S.); the Ryan White Center for Pediatric Infectious Disease and Global Health, Department of Pediatrics, Indiana University School of Medicine, Indianapolis (S.S.B.); the Department of Pediatrics, Division of Critical Care Medicine, University of Texas Southwestern, Children's Medical Center, Dallas (M.M.); the Division of Pediatric Critical Care, University of Minnesota Masonic Children's Hospital, Minneapolis (J.R.H.), and the Divisions of Pediatric Infectious Diseases and Pediatric Critical Care Medicine, Department of Pediatric and Adolescent Medicine, Mayo Clinic, Rochester (E.R.L.) - both in Minnesota; the Division of Pediatric Critical Care, Department of Pediatrics, University of Utah, Salt Lake City (H.C.); the Department of Pediatrics, Division of Cardiology, Louisiana State University Health Sciences Center and Children's Hospital of New Orleans, New Orleans (T.T.B.); the Division of Pediatric Critical Care, Department of Pediatrics, Children's Hospital and Medical Center, Omaha, NE (M.L.C.); and the Division of Pediatric Critical Care Medicine, Department of Pediatrics, University of Alabama at Birmingham, Birmingham (M.K.).

Publisher: Massachusetts Medical Society Country of Publication: United States NLM ID: 0255562 Publication Model: Print-Electronic Cited Medium: Internet ISSN: 1533-4406 (Electronic) Linking ISSN: 00284793 NLM ISO Abbreviation: N Engl J Med Subsets: MEDLINE

Price AM; From the Covid-19 Response Team, Centers for Disease Control and Prevention (A.M.P., S.M.O., M.W.T., L.D.Z., A.P.C., M.M.P.), the Center for Childhood Infections and Vaccines of Children's Healthcare of Atlanta and the Department of Pediatrics, Emory University School of Medicine (S.K.), and the Division of Critical Care Medicine, Department of Pediatrics, Emory University School of Medicine, Children's Healthcare of Atlanta (K.M.T.) - all in Atlanta; the Department of Anesthesiology, Critical Care, and Pain Medicine, Boston Children's Hospital (M.M.N., A.G.R.), and the Departments of Anaesthesia and Pediatrics, Harvard Medical School (A.G.R.) - both in Boston; the Division of Pediatric Infectious Diseases, Department of Pediatrics, Vanderbilt University Medical Center, Nashville (N.B.H.); the Department of Pediatrics, Baylor College of Medicine, Immunization Project, Texas Children's Hospital, Houston (J.A.B., L.C.S.), and the Department of Pediatrics, Division of Critical Care Medicine, University of Texas Southwestern, Children's Medical Center, Dallas (M.M.); the Division of Infectious Diseases, Children's Hospital Los Angeles and Departments of Pediatrics and Molecular Microbiology and Immunology, University of Southern California, Los Angeles (P.S.P.), the Division of Pediatric Hospital Medicine, UC San Diego-Rady Children's Hospital, San Diego (M.A.C.), the Division of Critical Care Medicine, UCSF Benioff Children's Hospital, Oakland (N.Z.C.), and the Department of Pediatrics, Divisions of Critical Care Medicine and Allergy, Immunology, and Bone Marrow Transplant, University of California, San Francisco, San Francisco (M.S.Z.) - all in California; Section of Pediatric Critical Care, Department of Pediatrics, Arkansas Children's Hospital, Little Rock (K.I.); the Division of Pediatric Critical Care Medicine, Nationwide Children's Hospital Columbus (K.E.B.), the Division of Critical Care Medicine, Department of Pediatrics, Akron Children's Hospital, Akron (R.A.N.), and the Department of Pediatrics, University of Cincinnati College of Medicine, Cincinnati Children's Hospital Medical Center, Cincinnati (M.A.S.) - all in Ohio; the Department of Pediatrics, Section of Critical Care Medicine, University of Colorado School of Medicine and Children's Hospital Colorado, Aurora (A.B.M.); the Department of Pediatrics, University of North Carolina at Chapel Hill Children's Hospital, Chapel Hill (T.C.W., S.P.S.); the Division of Pediatric Critical Care Medicine (E.H.M.) and the Department of Pediatrics (L.S.), Medical University of South Carolina, Charleston; the Division of Pediatric Infectious Diseases, Department of Pediatrics, Children's Mercy Kansas City, Kansas City, MO (J.E.S.); the Departments of Pediatrics and Microbiology, Division of Infectious Diseases, University of Mississippi Medical Center, Jackson (C.V.H.); the Department of Pediatrics, Division of Cardiology, Louisiana State University Health Sciences Center and Children's Hospital of New Orleans, New Orleans (T.T.B.); the Divisions of Pediatric Infectious Diseases and Pediatric Critical Care Medicine, Department of Pediatric and Adolescent Medicine, Mayo Clinic, Rochester (E.R.L.), and the Division of Pediatric Critical Care, University of Minnesota Masonic Children's Hospital, Minneapolis (J.R.H.) - both in Minnesota; the Division of Critical Care Medicine, Department of Anesthesiology and Critical Care, Children's Hospital of Philadelphia, Philadelphia (K.C.); the Ryan White Center for Pediatric Infectious Disease and Global Health, Department of Pediatrics, Indiana University School of Medicine, Indianapolis (S.S.B.); the Division of Pediatric Critical Care Medicine, Children's Hospital of Michigan, Central Michigan University, Detroit (S.M.H.), and the Division of Pediatric Critical Care Medicine, Department of Pediatrics, Mott Children's Hospital and University of Michigan, Ann Arbor (H.R.F.); the Division of Pediatric Critical Care, Department of Pediatrics, Children's Hospital and Medical Center, Omaha, NE (M.L.C.); the Division of Pediatric Critical Care, Department of Pediatrics, Cooperman Barnabas Medical Center, Livingston, NJ (S.J.G.); the Division of Critical Care Medicine, Department of Pediatrics, Northwestern University Feinberg School of Medicine, Ann and Robert H. Lurie Children's Hospital of Chicago, Chicago (B.M. Coates); the Division of Pediatric Critical Care Medicine, Department of Pediatrics, University of Alabama at Birmingham, Birmingham (M.K.); the Division of Pediatric Infectious Diseases, Department of Pediatrics, UHealth Holtz Children's Hospital, Miami (B.M. Chatani); and the Department of Pediatrics and Banner Children's at Diamond Children's Medical Center, University of Arizona, Tucson (K.V.T.).; Olson SM; From the Covid-19 Response Team, Centers for Disease Control and Prevention (A.M.P., S.M.O., M.W.T., L.D.Z., A.P.C., M.M.P.), the Center for Childhood Infections and Vaccines of Children's Healthcare of Atlanta and the Department of Pediatrics, Emory University School of Medicine (S.K.), and the Division of Critical Care Medicine, Department of Pediatrics, Emory University School of Medicine, Children's Healthcare of Atlanta (K.M.T.) - all in Atlanta; the Department of Anesthesiology, Critical Care, and Pain Medicine, Boston Children's Hospital (M.M.N., A.G.R.), and the Departments of Anaesthesia and Pediatrics, Harvard Medical School (A.G.R.) - both in Boston; the Division of Pediatric Infectious Diseases, Department of Pediatrics, Vanderbilt University Medical Center, Nashville (N.B.H.); the Department of Pediatrics, Baylor College of Medicine, Immunization Project, Texas Children's Hospital, Houston (J.A.B., L.C.S.), and the Department of Pediatrics, Division of Critical Care Medicine, University of Texas Southwestern, Children's Medical Center, Dallas (M.M.); the Division of Infectious Diseases, Children's Hospital Los Angeles and Departments of Pediatrics and Molecular Microbiology and Immunology, University of Southern California, Los Angeles (P.S.P.), the Division of Pediatric Hospital Medicine, UC San Diego-Rady Children's Hospital, San Diego (M.A.C.), the Division of Critical Care Medicine, UCSF Benioff Children's Hospital, Oakland (N.Z.C.), and the Department of Pediatrics, Divisions of Critical Care Medicine and Allergy, Immunology, and Bone Marrow Transplant, University of California, San Francisco, San Francisco (M.S.Z.) - all in California; Section of Pediatric Critical Care, Department of Pediatrics, Arkansas Children's Hospital, Little Rock (K.I.); the Division of Pediatric Critical Care Medicine, Nationwide Children's Hospital Columbus (K.E.B.), the Division of Critical Care Medicine, Department of Pediatrics, Akron Children's Hospital, Akron (R.A.N.), and the Department of Pediatrics, University of Cincinnati College of Medicine, Cincinnati Children's Hospital Medical Center, Cincinnati (M.A.S.) - all in Ohio; the Department of Pediatrics, Section of Critical Care Medicine, University of Colorado School of Medicine and Children's Hospital Colorado, Aurora (A.B.M.); the Department of Pediatrics, University of North Carolina at Chapel Hill Children's Hospital, Chapel Hill (T.C.W., S.P.S.); the Division of Pediatric Critical Care Medicine (E.H.M.) and the Department of Pediatrics (L.S.), Medical University of South Carolina, Charleston; the Division of Pediatric Infectious Diseases, Department of Pediatrics, Children's Mercy Kansas City, Kansas City, MO (J.E.S.); the Departments of Pediatrics and Microbiology, Division of Infectious Diseases, University of Mississippi Medical Center, Jackson (C.V.H.); the Department of Pediatrics, Division of Cardiology, Louisiana State University Health Sciences Center and Children's Hospital of New Orleans, New Orleans (T.T.B.); the Divisions of Pediatric Infectious Diseases and Pediatric Critical Care Medicine, Department of Pediatric and Adolescent Medicine, Mayo Clinic, Rochester (E.R.L.), and the Division of Pediatric Critical Care, University of Minnesota Masonic Children's Hospital, Minneapolis (J.R.H.) - both in Minnesota; the Division of Critical Care Medicine, Department of Anesthesiology and Critical Care, Children's Hospital of Philadelphia, Philadelphia (K.C.); the Ryan White Center for Pediatric Infectious Disease and Global Health, Department of Pediatrics, Indiana University School of Medicine, Indianapolis (S.S.B.); the Division of Pediatric Critical Care Medicine, Children's Hospital of Michigan, Central Michigan University, Detroit (S.M.H.), and the Division of Pediatric Critical Care Medicine, Department of Pediatrics, Mott Children's Hospital and University of Michigan, Ann Arbor (H.R.F.); the Division of Pediatric Critical Care, Department of Pediatrics, Children's Hospital and Medical Center, Omaha, NE (M.L.C.); the Division of Pediatric Critical Care, Department of Pediatrics, Cooperman Barnabas Medical Center, Livingston, NJ (S.J.G.); the Division of Critical Care Medicine, Department of Pediatrics, Northwestern University Feinberg School of Medicine, Ann and Robert H. Lurie Children's Hospital of Chicago, Chicago (B.M. Coates); the Division of Pediatric Critical Care Medicine, Department of Pediatrics, University of Alabama at Birmingham, Birmingham (M.K.); the Division of Pediatric Infectious Diseases, Department of Pediatrics, UHealth Holtz Children's Hospital, Miami (B.M. Chatani); and the Department of Pediatrics and Banner Children's at Diamond Children's Medical Center, University of Arizona, Tucson (K.V.T.).; Newhams MM; From the Covid-19 Response Team, Centers for Disease Control and Prevention (A.M.P., S.M.O., M.W.T., L.D.Z., A.P.C., M.M.P.), the Center for Childhood Infections and Vaccines of Children's Healthcare of Atlanta and the Department of Pediatrics, Emory University School of Medicine (S.K.), and the Division of Critical Care Medicine, Department of Pediatrics, Emory University School of Medicine, Children's Healthcare of Atlanta (K.M.T.) - all in Atlanta; the Department of Anesthesiology, Critical Care, and Pain Medicine, Boston Children's Hospital (M.M.N., A.G.R.), and the Departments of Anaesthesia and Pediatrics, Harvard Medical School (A.G.R.) - both in Boston; the Division of Pediatric Infectious Diseases, Department of Pediatrics, Vanderbilt University Medical Center, Nashville (N.B.H.); the Department of Pediatrics, Baylor College of Medicine, Immunization Project, Texas Children's Hospital, Houston (J.A.B., L.C.S.), and the Department of Pediatrics, Division of Critical Care Medicine, University of Texas Southwestern, Children's Medical Center, Dallas (M.M.); the Division of Infectious Diseases, Children's Hospital Los Angeles and Departments of Pediatrics and Molecular Microbiology and Immunology, University of Southern California, Los Angeles (P.S.P.), the Division of Pediatric Hospital Medicine, UC San Diego-Rady Children's Hospital, San Diego (M.A.C.), the Division of Critical Care Medicine, UCSF Benioff Children's Hospital, Oakland (N.Z.C.), and the Department of Pediatrics, Divisions of Critical Care Medicine and Allergy, Immunology, and Bone Marrow Transplant, University of California, San Francisco, San Francisco (M.S.Z.) - all in California; Section of Pediatric Critical Care, Department of Pediatrics, Arkansas Children's Hospital, Little Rock (K.I.); the Division of Pediatric Critical Care Medicine, Nationwide Children's Hospital Columbus (K.E.B.), the Division of Critical Care Medicine, Department of Pediatrics, Akron Children's Hospital, Akron (R.A.N.), and the Department of Pediatrics, University of Cincinnati College of Medicine, Cincinnati Children's Hospital Medical Center, Cincinnati (M.A.S.) - all in Ohio; the Department of Pediatrics, Section of Critical Care Medicine, University of Colorado School of Medicine and Children's Hospital Colorado, Aurora (A.B.M.); the Department of Pediatrics, University of North Carolina at Chapel Hill Children's Hospital, Chapel Hill (T.C.W., S.P.S.); the Division of Pediatric Critical Care Medicine (E.H.M.) and the Department of Pediatrics (L.S.), Medical University of South Carolina, Charleston; the Division of Pediatric Infectious Diseases, Department of Pediatrics, Children's Mercy Kansas City, Kansas City, MO (J.E.S.); the Departments of Pediatrics and Microbiology, Division of Infectious Diseases, University of Mississippi Medical Center, Jackson (C.V.H.); the Department of Pediatrics, Division of Cardiology, Louisiana State University Health Sciences Center and Children's Hospital of New Orleans, New Orleans (T.T.B.); the Divisions of Pediatric Infectious Diseases and Pediatric Critical Care Medicine, Department of Pediatric and Adolescent Medicine, Mayo Clinic, Rochester (E.R.L.), and the Division of Pediatric Critical Care, University of Minnesota Masonic Children's Hospital, Minneapolis (J.R.H.) - both in Minnesota; the Division of Critical Care Medicine, Department of Anesthesiology and Critical Care, Children's Hospital of Philadelphia, Philadelphia (K.C.); the Ryan White Center for Pediatric Infectious Disease and Global Health, Department of Pediatrics, Indiana University School of Medicine, Indianapolis (S.S.B.); the Division of Pediatric Critical Care Medicine, Children's Hospital of Michigan, Central Michigan University, Detroit (S.M.H.), and the Division of Pediatric Critical Care Medicine, Department of Pediatrics, Mott Children's Hospital and University of Michigan, Ann Arbor (H.R.F.); the Division of Pediatric Critical Care, Department of Pediatrics, Children's Hospital and Medical Center, Omaha, NE (M.L.C.); the Division of Pediatric Critical Care, Department of Pediatrics, Cooperman Barnabas Medical Center, Livingston, NJ (S.J.G.); the Division of Critical Care Medicine, Department of Pediatrics, Northwestern University Feinberg School of Medicine, Ann and Robert H. Lurie Children's Hospital of Chicago, Chicago (B.M. Coates); the Division of Pediatric Critical Care Medicine, Department of Pediatrics, University of Alabama at Birmingham, Birmingham (M.K.); the Division of Pediatric Infectious Diseases, Department of Pediatrics, UHealth Holtz Children's Hospital, Miami (B.M. Chatani); and the Department of Pediatrics and Banner Children's at Diamond Children's Medical Center, University of Arizona, Tucson (K.V.T.).; Halasa NB; From the Covid-19 Response Team, Centers for Disease Control and Prevention (A.M.P., S.M.O., M.W.T., L.D.Z., A.P.C., M.M.P.), the Center for Childhood Infections and Vaccines of Children's Healthcare of Atlanta and the Department of Pediatrics, Emory University School of Medicine (S.K.), and the Division of Critical Care Medicine, Department of Pediatrics, Emory University School of Medicine, Children's Healthcare of Atlanta (K.M.T.) - all in Atlanta; the Department of Anesthesiology, Critical Care, and Pain Medicine, Boston Children's Hospital (M.M.N., A.G.R.), and the Departments of Anaesthesia and Pediatrics, Harvard Medical School (A.G.R.) - both in Boston; the Division of Pediatric Infectious Diseases, Department of Pediatrics, Vanderbilt University Medical Center, Nashville (N.B.H.); the Department of Pediatrics, Baylor College of Medicine, Immunization Project, Texas Children's Hospital, Houston (J.A.B., L.C.S.), and the Department of Pediatrics, Division of Critical Care Medicine, University of Texas Southwestern, Children's Medical Center, Dallas (M.M.); the Division of Infectious Diseases, Children's Hospital Los Angeles and Departments of Pediatrics and Molecular Microbiology and Immunology, University of Southern California, Los Angeles (P.S.P.), the Division of Pediatric Hospital Medicine, UC San Diego-Rady Children's Hospital, San Diego (M.A.C.), the Division of Critical Care Medicine, UCSF Benioff Children's Hospital, Oakland (N.Z.C.), and the Department of Pediatrics, Divisions of Critical Care Medicine and Allergy, Immunology, and Bone Marrow Transplant, University of California, San Francisco, San Francisco (M.S.Z.) - all in California; Section of Pediatric Critical Care, Department of Pediatrics, Arkansas Children's Hospital, Little Rock (K.I.); the Division of Pediatric Critical Care Medicine, Nationwide Children's Hospital Columbus (K.E.B.), the Division of Critical Care Medicine, Department of Pediatrics, Akron Children's Hospital, Akron (R.A.N.), and the Department of Pediatrics, University of Cincinnati College of Medicine, Cincinnati Children's Hospital Medical Center, Cincinnati (M.A.S.) - all in Ohio; the Department of Pediatrics, Section of Critical Care Medicine, University of Colorado School of Medicine and Children's Hospital Colorado, Aurora (A.B.M.); the Department of Pediatrics, University of North Carolina at Chapel Hill Children's Hospital, Chapel Hill (T.C.W., S.P.S.); the Division of Pediatric Critical Care Medicine (E.H.M.) and the Department of Pediatrics (L.S.), Medical University of South Carolina, Charleston; the Division of Pediatric Infectious Diseases, Department of Pediatrics, Children's Mercy Kansas City, Kansas City, MO (J.E.S.); the Departments of Pediatrics and Microbiology, Division of Infectious Diseases, University of Mississippi Medical Center, Jackson (C.V.H.); the Department of Pediatrics, Division of Cardiology, Louisiana State University Health Sciences Center and Children's Hospital of New Orleans, New Orleans (T.T.B.); the Divisions of Pediatric Infectious Diseases and Pediatric Critical Care Medicine, Department of Pediatric and Adolescent Medicine, Mayo Clinic, Rochester (E.R.L.), and the Division of Pediatric Critical Care, University of Minnesota Masonic Children's Hospital, Minneapolis (J.R.H.) - both in Minnesota; the Division of Critical Care Medicine, Department of Anesthesiology and Critical Care, Children's Hospital of Philadelphia, Philadelphia (K.C.); the Ryan White Center for Pediatric Infectious Disease and Global Health, Department of Pediatrics, Indiana University School of Medicine, Indianapolis (S.S.B.); the Division of Pediatric Critical Care Medicine, Children's Hospital of Michigan, Central Michigan University, Detroit (S.M.H.), and the Division of Pediatric Critical Care Medicine, Department of Pediatrics, Mott Children's Hospital and University of Michigan, Ann Arbor (H.R.F.); the Division of Pediatric Critical Care, Department of Pediatrics, Children's Hospital and Medical Center, Omaha, NE (M.L.C.); the Division of Pediatric Critical Care, Department of Pediatrics, Cooperman Barnabas Medical Center, Livingston, NJ (S.J.G.); the Division of Critical Care Medicine, Department of Pediatrics, Northwestern University Feinberg School of Medicine, Ann and Robert H. Lurie Children's Hospital of Chicago, Chicago (B.M. Coates); the Division of Pediatric Critical Care Medicine, Department of Pediatrics, University of Alabama at Birmingham, Birmingham (M.K.); the Division of Pediatric Infectious Diseases, Department of Pediatrics, UHealth Holtz Children's Hospital, Miami (B.M. Chatani); and the Department of Pediatrics and Banner Children's at Diamond Children's Medical Center, University of Arizona, Tucson (K.V.T.).; Boom JA; From the Covid-19 Response Team, Centers for Disease Control and Prevention (A.M.P., S.M.O., M.W.T., L.D.Z., A.P.C., M.M.P.), the Center for Childhood Infections and Vaccines of Children's Healthcare of Atlanta and the Department of Pediatrics, Emory University School of Medicine (S.K.), and the Division of Critical Care Medicine, Department of Pediatrics, Emory University School of Medicine, Children's Healthcare of Atlanta (K.M.T.) - all in Atlanta; the Department of Anesthesiology, Critical Care, and Pain Medicine, Boston Children's Hospital (M.M.N., A.G.R.), and the Departments of Anaesthesia and Pediatrics, Harvard Medical School (A.G.R.) - both in Boston; the Division of Pediatric Infectious Diseases, Department of Pediatrics, Vanderbilt University Medical Center, Nashville (N.B.H.); the Department of Pediatrics, Baylor College of Medicine, Immunization Project, Texas Children's Hospital, Houston (J.A.B., L.C.S.), and the Department of Pediatrics, Division of Critical Care Medicine, University of Texas Southwestern, Children's Medical Center, Dallas (M.M.); the Division of Infectious Diseases, Children's Hospital Los Angeles and Departments of Pediatrics and Molecular Microbiology and Immunology, University of Southern California, Los Angeles (P.S.P.), the Division of Pediatric Hospital Medicine, UC San Diego-Rady Children's Hospital, San Diego (M.A.C.), the Division of Critical Care Medicine, UCSF Benioff Children's Hospital, Oakland (N.Z.C.), and the Department of Pediatrics, Divisions of Critical Care Medicine and Allergy, Immunology, and Bone Marrow Transplant, University of California, San Francisco, San Francisco (M.S.Z.) - all in California; Section of Pediatric Critical Care, Department of Pediatrics, Arkansas Children's Hospital, Little Rock (K.I.); the Division of Pediatric Critical Care Medicine, Nationwide Children's Hospital Columbus (K.E.B.), the Division of Critical Care Medicine, Department of Pediatrics, Akron Children's Hospital, Akron (R.A.N.), and the Department of Pediatrics, University of Cincinnati College of Medicine, Cincinnati Children's Hospital Medical Center, Cincinnati (M.A.S.) - all in Ohio; the Department of Pediatrics, Section of Critical Care Medicine, University of Colorado School of Medicine and Children's Hospital Colorado, Aurora (A.B.M.); the Department of Pediatrics, University of North Carolina at Chapel Hill Children's Hospital, Chapel Hill (T.C.W., S.P.S.); the Division of Pediatric Critical Care Medicine (E.H.M.) and the Department of Pediatrics (L.S.), Medical University of South Carolina, Charleston; the Division of Pediatric Infectious Diseases, Department of Pediatrics, Children's Mercy Kansas City, Kansas City, MO (J.E.S.); the Departments of Pediatrics and Microbiology, Division of Infectious Diseases, University of Mississippi Medical Center, Jackson (C.V.H.); the Department of Pediatrics, Division of Cardiology, Louisiana State University Health Sciences Center and Children's Hospital of New Orleans, New Orleans (T.T.B.); the Divisions of Pediatric Infectious Diseases and Pediatric Critical Care Medicine, Department of Pediatric and Adolescent Medicine, Mayo Clinic, Rochester (E.R.L.), and the Division of Pediatric Critical Care, University of Minnesota Masonic Children's Hospital, Minneapolis (J.R.H.) - both in Minnesota; the Division of Critical Care Medicine, Department of Anesthesiology and Critical Care, Children's Hospital of Philadelphia, Philadelphia (K.C.); the Ryan White Center for Pediatric Infectious Disease and Global Health, Department of Pediatrics, Indiana University School of Medicine, Indianapolis (S.S.B.); the Division of Pediatric Critical Care Medicine, Children's Hospital of Michigan, Central Michigan University, Detroit (S.M.H.), and the Division of Pediatric Critical Care Medicine, Department of Pediatrics, Mott Children's Hospital and University of Michigan, Ann Arbor (H.R.F.); the Division of Pediatric Critical Care, Department of Pediatrics, Children's Hospital and Medical Center, Omaha, NE (M.L.C.); the Division of Pediatric Critical Care, Department of Pediatrics, Cooperman Barnabas Medical Center, Livingston, NJ (S.J.G.); the Division of Critical Care Medicine, Department of Pediatrics, Northwestern University Feinberg School of Medicine, Ann and Robert H. Lurie Children's Hospital of Chicago, Chicago (B.M. Coates); the Division of Pediatric Critical Care Medicine, Department of Pediatrics, University of Alabama at Birmingham, Birmingham (M.K.); the Division of Pediatric Infectious Diseases, Department of Pediatrics, UHealth Holtz Children's Hospital, Miami (B.M. Chatani); and the Department of Pediatrics and Banner Children's at Diamond Children's Medical Center, University of Arizona, Tucson (K.V.T.).; Sahni LC; From the Covid-19 Response Team, Centers for Disease Control and Prevention (A.M.P., S.M.O., M.W.T., L.D.Z., A.P.C., M.M.P.), the Center for Childhood Infections and Vaccines of Children's Healthcare of Atlanta and the Department of Pediatrics, Emory University School of Medicine (S.K.), and the Division of Critical Care Medicine, Department of Pediatrics, Emory University School of Medicine, Children's Healthcare of Atlanta (K.M.T.) - all in Atlanta; the Department of Anesthesiology, Critical Care, and Pain Medicine, Boston Children's Hospital (M.M.N., A.G.R.), and the Departments of Anaesthesia and Pediatrics, Harvard Medical School (A.G.R.) - both in Boston; the Division of Pediatric Infectious Diseases, Department of Pediatrics, Vanderbilt University Medical Center, Nashville (N.B.H.); the Department of Pediatrics, Baylor College of Medicine, Immunization Project, Texas Children's Hospital, Houston (J.A.B., L.C.S.), and the Department of Pediatrics, Division of Critical Care Medicine, University of Texas Southwestern, Children's Medical Center, Dallas (M.M.); the Division of Infectious Diseases, Children's Hospital Los Angeles and Departments of Pediatrics and Molecular Microbiology and Immunology, University of Southern California, Los Angeles (P.S.P.), the Division of Pediatric Hospital Medicine, UC San Diego-Rady Children's Hospital, San Diego (M.A.C.), the Division of Critical Care Medicine, UCSF Benioff Children's Hospital, Oakland (N.Z.C.), and the Department of Pediatrics, Divisions of Critical Care Medicine and Allergy, Immunology, and Bone Marrow Transplant, University of California, San Francisco, San Francisco (M.S.Z.) - all in California; Section of Pediatric Critical Care, Department of Pediatrics, Arkansas Children's Hospital, Little Rock (K.I.); the Division of Pediatric Critical Care Medicine, Nationwide Children's Hospital Columbus (K.E.B.), the Division of Critical Care Medicine, Department of Pediatrics, Akron Children's Hospital, Akron (R.A.N.), and the Department of Pediatrics, University of Cincinnati College of Medicine, Cincinnati Children's Hospital Medical Center, Cincinnati (M.A.S.) - all in Ohio; the Department of Pediatrics, Section of Critical Care Medicine, University of Colorado School of Medicine and Children's Hospital Colorado, Aurora (A.B.M.); the Department of Pediatrics, University of North Carolina at Chapel Hill Children's Hospital, Chapel Hill (T.C.W., S.P.S.); the Division of Pediatric Critical Care Medicine (E.H.M.) and the Department of Pediatrics (L.S.), Medical University of South Carolina, Charleston; the Division of Pediatric Infectious Diseases, Department of Pediatrics, Children's Mercy Kansas City, Kansas City, MO (J.E.S.); the Departments of Pediatrics and Microbiology, Division of Infectious Diseases, University of Mississippi Medical Center, Jackson (C.V.H.); the Department of Pediatrics, Division of Cardiology, Louisiana State University Health Sciences Center and Children's Hospital of New Orleans, New Orleans (T.T.B.); the Divisions of Pediatric Infectious Diseases and Pediatric Critical Care Medicine, Department of Pediatric and Adolescent Medicine, Mayo Clinic, Rochester (E.R.L.), and the Division of Pediatric Critical Care, University of Minnesota Masonic Children's Hospital, Minneapolis (J.R.H.) - both in Minnesota; the Division of Critical Care Medicine, Department of Anesthesiology and Critical Care, Children's Hospital of Philadelphia, Philadelphia (K.C.); the Ryan White Center for Pediatric Infectious Disease and Global Health, Department of Pediatrics, Indiana University School of Medicine, Indianapolis (S.S.B.); the Division of Pediatric Critical Care Medicine, Children's Hospital of Michigan, Central Michigan University, Detroit (S.M.H.), and the Division of Pediatric Critical Care Medicine, Department of Pediatrics, Mott Children's Hospital and University of Michigan, Ann Arbor (H.R.F.); the Division of Pediatric Critical Care, Department of Pediatrics, Children's Hospital and Medical Center, Omaha, NE (M.L.C.); the Division of Pediatric Critical Care, Department of Pediatrics, Cooperman Barnabas Medical Center, Livingston, NJ (S.J.G.); the Division of Critical Care Medicine, Department of Pediatrics, Northwestern University Feinberg School of Medicine, Ann and Robert H. Lurie Children's Hospital of Chicago, Chicago (B.M. Coates); the Division of Pediatric Critical Care Medicine, Department of Pediatrics, University of Alabama at Birmingham, Birmingham (M.K.); the Division of Pediatric Infectious Diseases, Department of Pediatrics, UHealth Holtz Children's Hospital, Miami (B.M. Chatani); and the Department of Pediatrics and Banner Children's at Diamond Children's Medical Center, University of Arizona, Tucson (K.V.T.).; Pannaraj PS; From the Covid-19 Response Team, Centers for Disease Control and Prevention (A.M.P., S.M.O., M.W.T., L.D.Z., A.P.C., M.M.P.), the Center for Childhood Infections and Vaccines of Children's Healthcare of Atlanta and the Department of Pediatrics, Emory University School of Medicine (S.K.), and the Division of Critical Care Medicine, Department of Pediatrics, Emory University School of Medicine, Children's Healthcare of Atlanta (K.M.T.) - all in Atlanta; the Department of Anesthesiology, Critical Care, and Pain Medicine, Boston Children's Hospital (M.M.N., A.G.R.), and the Departments of Anaesthesia and Pediatrics, Harvard Medical School (A.G.R.) - both in Boston; the Division of Pediatric Infectious Diseases, Department of Pediatrics, Vanderbilt University Medical Center, Nashville (N.B.H.); the Department of Pediatrics, Baylor College of Medicine, Immunization Project, Texas Children's Hospital, Houston (J.A.B., L.C.S.), and the Department of Pediatrics, Division of Critical Care Medicine, University of Texas Southwestern, Children's Medical Center, Dallas (M.M.); the Division of Infectious Diseases, Children's Hospital Los Angeles and Departments of Pediatrics and Molecular Microbiology and Immunology, University of Southern California, Los Angeles (P.S.P.), the Division of Pediatric Hospital Medicine, UC San Diego-Rady Children's Hospital, San Diego (M.A.C.), the Division of Critical Care Medicine, UCSF Benioff Children's Hospital, Oakland (N.Z.C.), and the Department of Pediatrics, Divisions of Critical Care Medicine and Allergy, Immunology, and Bone Marrow Transplant, University of California, San Francisco, San Francisco (M.S.Z.) - all in California; Section of Pediatric Critical Care, Department of Pediatrics, Arkansas Children's Hospital, Little Rock (K.I.); the Division of Pediatric Critical Care Medicine, Nationwide Children's Hospital Columbus (K.E.B.), the Division of Critical Care Medicine, Department of Pediatrics, Akron Children's Hospital, Akron (R.A.N.), and the Department of Pediatrics, University of Cincinnati College of Medicine, Cincinnati Children's Hospital Medical Center, Cincinnati (M.A.S.) - all in Ohio; the Department of Pediatrics, Section of Critical Care Medicine, University of Colorado School of Medicine and Children's Hospital Colorado, Aurora (A.B.M.); the Department of Pediatrics, University of North Carolina at Chapel Hill Children's Hospital, Chapel Hill (T.C.W., S.P.S.); the Division of Pediatric Critical Care Medicine (E.H.M.) and the Department of Pediatrics (L.S.), Medical University of South Carolina, Charleston; the Division of Pediatric Infectious Diseases, Department of Pediatrics, Children's Mercy Kansas City, Kansas City, MO (J.E.S.); the Departments of Pediatrics and Microbiology, Division of Infectious Diseases, University of Mississippi Medical Center, Jackson (C.V.H.); the Department of Pediatrics, Division of Cardiology, Louisiana State University Health Sciences Center and Children's Hospital of New Orleans, New Orleans (T.T.B.); the Divisions of Pediatric Infectious Diseases and Pediatric Critical Care Medicine, Department of Pediatric and Adolescent Medicine, Mayo Clinic, Rochester (E.R.L.), and the Division of Pediatric Critical Care, University of Minnesota Masonic Children's Hospital, Minneapolis (J.R.H.) - both in Minnesota; the Division of Critical Care Medicine, Department of Anesthesiology and Critical Care, Children's Hospital of Philadelphia, Philadelphia (K.C.); the Ryan White Center for Pediatric Infectious Disease and Global Health, Department of Pediatrics, Indiana University School of Medicine, Indianapolis (S.S.B.); the Division of Pediatric Critical Care Medicine, Children's Hospital of Michigan, Central Michigan University, Detroit (S.M.H.), and the Division of Pediatric Critical Care Medicine, Department of Pediatrics, Mott Children's Hospital and University of Michigan, Ann Arbor (H.R.F.); the Division of Pediatric Critical Care, Department of Pediatrics, Children's Hospital and Medical Center, Omaha, NE (M.L.C.); the Division of Pediatric Critical Care, Department of Pediatrics, Cooperman Barnabas Medical Center, Livingston, NJ (S.J.G.); the Division of Critical Care Medicine, Department of Pediatrics, Northwestern University Feinberg School of Medicine, Ann and Robert H. Lurie Children's Hospital of Chicago, Chicago (B.M. Coates); the Division of Pediatric Critical Care Medicine, Department of Pediatrics, University of Alabama at Birmingham, Birmingham (M.K.); the Division of Pediatric Infectious Diseases, Department of Pediatrics, UHealth Holtz Children's Hospital, Miami (B.M. Chatani); and the Department of Pediatrics and Banner Children's at Diamond Children's Medical Center, University of Arizona, Tucson (K.V.T.).; Irby K; From the Covid-19 Response Team, Centers for Disease Control and Prevention (A.M.P., S.M.O., M.W.T., L.D.Z., A.P.C., M.M.P.), the Center for Childhood Infections and Vaccines of Children's Healthcare of Atlanta and the Department of Pediatrics, Emory University School of Medicine (S.K.), and the Division of Critical Care Medicine, Department of Pediatrics, Emory University School of Medicine, Children's Healthcare of Atlanta (K.M.T.) - all in Atlanta; the Department of Anesthesiology, Critical Care, and Pain Medicine, Boston Children's Hospital (M.M.N., A.G.R.), and the Departments of Anaesthesia and Pediatrics, Harvard Medical School (A.G.R.) - both in Boston; the Division of Pediatric Infectious Diseases, Department of Pediatrics, Vanderbilt University Medical Center, Nashville (N.B.H.); the Department of Pediatrics, Baylor College of Medicine, Immunization Project, Texas Children's Hospital, Houston (J.A.B., L.C.S.), and the Department of Pediatrics, Division of Critical Care Medicine, University of Texas Southwestern, Children's Medical Center, Dallas (M.M.); the Division of Infectious Diseases, Children's Hospital Los Angeles and Departments of Pediatrics and Molecular Microbiology and Immunology, University of Southern California, Los Angeles (P.S.P.), the Division of Pediatric Hospital Medicine, UC San Diego-Rady Children's Hospital, San Diego (M.A.C.), the Division of Critical Care Medicine, UCSF Benioff Children's Hospital, Oakland (N.Z.C.), and the Department of Pediatrics, Divisions of Critical Care Medicine and Allergy, Immunology, and Bone Marrow Transplant, University of California, San Francisco, San Francisco (M.S.Z.) - all in California; Section of Pediatric Critical Care, Department of Pediatrics, Arkansas Children's Hospital, Little Rock (K.I.); the Division of Pediatric Critical Care Medicine, Nationwide Children's Hospital Columbus (K.E.B.), the Division of Critical Care Medicine, Department of Pediatrics, Akron Children's Hospital, Akron (R.A.N.), and the Department of Pediatrics, University of Cincinnati College of Medicine, Cincinnati Children's Hospital Medical Center, Cincinnati (M.A.S.) - all in Ohio; the Department of Pediatrics, Section of Critical Care Medicine, University of Colorado School of Medicine and Children's Hospital Colorado, Aurora (A.B.M.); the Department of Pediatrics, University of North Carolina at Chapel Hill Children's Hospital, Chapel Hill (T.C.W., S.P.S.); the Division of Pediatric Critical Care Medicine (E.H.M.) and the Department of Pediatrics (L.S.), Medical University of South Carolina, Charleston; the Division of Pediatric Infectious Diseases, Department of Pediatrics, Children's Mercy Kansas City, Kansas City, MO (J.E.S.); the Departments of Pediatrics and Microbiology, Division of Infectious Diseases, University of Mississippi Medical Center, Jackson (C.V.H.); the Department of Pediatrics, Division of Cardiology, Louisiana State University Health Sciences Center and Children's Hospital of New Orleans, New Orleans (T.T.B.); the Divisions of Pediatric Infectious Diseases and Pediatric Critical Care Medicine, Department of Pediatric and Adolescent Medicine, Mayo Clinic, Rochester (E.R.L.), and the Division of Pediatric Critical Care, University of Minnesota Masonic Children's Hospital, Minneapolis (J.R.H.) - both in Minnesota; the Division of Critical Care Medicine, Department of Anesthesiology and Critical Care, Children's Hospital of Philadelphia, Philadelphia (K.C.); the Ryan White Center for Pediatric Infectious Disease and Global Health, Department of Pediatrics, Indiana University School of Medicine, Indianapolis (S.S.B.); the Division of Pediatric Critical Care Medicine, Children's Hospital of Michigan, Central Michigan University, Detroit (S.M.H.), and the Division of Pediatric Critical Care Medicine, Department of Pediatrics, Mott Children's Hospital and University of Michigan, Ann Arbor (H.R.F.); the Division of Pediatric Critical Care, Department of Pediatrics, Children's Hospital and Medical Center, Omaha, NE (M.L.C.); the Division of Pediatric Critical Care, Department of Pediatrics, Cooperman Barnabas Medical Center, Livingston, NJ (S.J.G.); the Division of Critical Care Medicine, Department of Pediatrics, Northwestern University Feinberg School of Medicine, Ann and Robert H. Lurie Children's Hospital of Chicago, Chicago (B.M. Coates); the Division of Pediatric Critical Care Medicine, Department of Pediatrics, University of Alabama at Birmingham, Birmingham (M.K.); the Division of Pediatric Infectious Diseases, Department of Pediatrics, UHealth Holtz Children's Hospital, Miami (B.M. Chatani); and the Department of Pediatrics and Banner Children's at Diamond Children's Medical Center, University of Arizona, Tucson (K.V.T.).; Bline KE; From the Covid-19 Response Team, Centers for Disease Control and Prevention (A.M.P., S.M.O., M.W.T., L.D.Z., A.P.C., M.M.P.), the Center for Childhood Infections and Vaccines of Children's Healthcare of Atlanta and the Department of Pediatrics, Emory University School of Medicine (S.K.), and the Division of Critical Care Medicine, Department of Pediatrics, Emory University School of Medicine, Children's Healthcare of Atlanta (K.M.T.) - all in Atlanta; the Department of Anesthesiology, Critical Care, and Pain Medicine, Boston Children's Hospital (M.M.N., A.G.R.), and the Departments of Anaesthesia and Pediatrics, Harvard Medical School (A.G.R.) - both in Boston; the Division of Pediatric Infectious Diseases, Department of Pediatrics, Vanderbilt University Medical Center, Nashville (N.B.H.); the Department of Pediatrics, Baylor College of Medicine, Immunization Project, Texas Children's Hospital, Houston (J.A.B., L.C.S.), and the Department of Pediatrics, Division of Critical Care Medicine, University of Texas Southwestern, Children's Medical Center, Dallas (M.M.); the Division of Infectious Diseases, Children's Hospital Los Angeles and Departments of Pediatrics and Molecular Microbiology and Immunology, University of Southern California, Los Angeles (P.S.P.), the Division of Pediatric Hospital Medicine, UC San Diego-Rady Children's Hospital, San Diego (M.A.C.), the Division of Critical Care Medicine, UCSF Benioff Children's Hospital, Oakland (N.Z.C.), and the Department of Pediatrics, Divisions of Critical Care Medicine and Allergy, Immunology, and Bone Marrow Transplant, University of California, San Francisco, San Francisco (M.S.Z.) - all in California; Section of Pediatric Critical Care, Department of Pediatrics, Arkansas Children's Hospital, Little Rock (K.I.); the Division of Pediatric Critical Care Medicine, Nationwide Children's Hospital Columbus (K.E.B.), the Division of Critical Care Medicine, Department of Pediatrics, Akron Children's Hospital, Akron (R.A.N.), and the Department of Pediatrics, University of Cincinnati College of Medicine, Cincinnati Children's Hospital Medical Center, Cincinnati (M.A.S.) - all in Ohio; the Department of Pediatrics, Section of Critical Care Medicine, University of Colorado School of Medicine and Children's Hospital Colorado, Aurora (A.B.M.); the Department of Pediatrics, University of North Carolina at Chapel Hill Children's Hospital, Chapel Hill (T.C.W., S.P.S.); the Division of Pediatric Critical Care Medicine (E.H.M.) and the Department of Pediatrics (L.S.), Medical University of South Carolina, Charleston; the Division of Pediatric Infectious Diseases, Department of Pediatrics, Children's Mercy Kansas City, Kansas City, MO (J.E.S.); the Departments of Pediatrics and Microbiology, Division of Infectious Diseases, University of Mississippi Medical Center, Jackson (C.V.H.); the Department of Pediatrics, Division of Cardiology, Louisiana State University Health Sciences Center and Children's Hospital of New Orleans, New Orleans (T.T.B.); the Divisions of Pediatric Infectious Diseases and Pediatric Critical Care Medicine, Department of Pediatric and Adolescent Medicine, Mayo Clinic, Rochester (E.R.L.), and the Division of Pediatric Critical Care, University of Minnesota Masonic Children's Hospital, Minneapolis (J.R.H.) - both in Minnesota; the Division of Critical Care Medicine, Department of Anesthesiology and Critical Care, Children's Hospital of Philadelphia, Philadelphia (K.C.); the Ryan White Center for Pediatric Infectious Disease and Global Health, Department of Pediatrics, Indiana University School of Medicine, Indianapolis (S.S.B.); the Division of Pediatric Critical Care Medicine, Children's Hospital of Michigan, Central Michigan University, Detroit (S.M.H.), and the Division of Pediatric Critical Care Medicine, Department of Pediatrics, Mott Children's Hospital and University of Michigan, Ann Arbor (H.R.F.); the Division of Pediatric Critical Care, Department of Pediatrics, Children's Hospital and Medical Center, Omaha, NE (M.L.C.); the Division of Pediatric Critical Care, Department of Pediatrics, Cooperman Barnabas Medical Center, Livingston, NJ (S.J.G.); the Division of Critical Care Medicine, Department of Pediatrics, Northwestern University Feinberg School of Medicine, Ann and Robert H. Lurie Children's Hospital of Chicago, Chicago (B.M. Coates); the Division of Pediatric Critical Care Medicine, Department of Pediatrics, University of Alabama at Birmingham, Birmingham (M.K.); the Division of Pediatric Infectious Diseases, Department of Pediatrics, UHealth Holtz Children's Hospital, Miami (B.M. Chatani); and the Department of Pediatrics and Banner Children's at Diamond Children's Medical Center, University of Arizona, Tucson (K.V.T.).; Maddux AB; From the Covid-19 Response Team, Centers for Disease Control and Prevention (A.M.P., S.M.O., M.W.T., L.D.Z., A.P.C., M.M.P.), the Center for Childhood Infections and Vaccines of Children's Healthcare of Atlanta and the Department of Pediatrics, Emory University School of Medicine (S.K.), and the Division of Critical Care Medicine, Department of Pediatrics, Emory University School of Medicine, Children's Healthcare of Atlanta (K.M.T.) - all in Atlanta; the Department of Anesthesiology, Critical Care, and Pain Medicine, Boston Children's Hospital (M.M.N., A.G.R.), and the Departments of Anaesthesia and Pediatrics, Harvard Medical School (A.G.R.) - both in Boston; the Division of Pediatric Infectious Diseases, Department of Pediatrics, Vanderbilt University Medical Center, Nashville (N.B.H.); the Department of Pediatrics, Baylor College of Medicine, Immunization Project, Texas Children's Hospital, Houston (J.A.B., L.C.S.), and the Department of Pediatrics, Division of Critical Care Medicine, University of Texas Southwestern, Children's Medical Center, Dallas (M.M.); the Division of Infectious Diseases, Children's Hospital Los Angeles and Departments of Pediatrics and Molecular Microbiology and Immunology, University of Southern California, Los Angeles (P.S.P.), the Division of Pediatric Hospital Medicine, UC San Diego-Rady Children's Hospital, San Diego (M.A.C.), the Division of Critical Care Medicine, UCSF Benioff Children's Hospital, Oakland (N.Z.C.), and the Department of Pediatrics, Divisions of Critical Care Medicine and Allergy, Immunology, and Bone Marrow Transplant, University of California, San Francisco, San Francisco (M.S.Z.) - all in California; Section of Pediatric Critical Care, Department of Pediatrics, Arkansas Children's Hospital, Little Rock (K.I.); the Division of Pediatric Critical Care Medicine, Nationwide Children's Hospital Columbus (K.E.B.), the Division of Critical Care Medicine, Department of Pediatrics, Akron Children's Hospital, Akron (R.A.N.), and the Department of Pediatrics, University of Cincinnati College of Medicine, Cincinnati Children's Hospital Medical Center, Cincinnati (M.A.S.) - all in Ohio; the Department of Pediatrics, Section of Critical Care Medicine, University of Colorado School of Medicine and Children's Hospital Colorado, Aurora (A.B.M.); the Department of Pediatrics, University of North Carolina at Chapel Hill Children's Hospital, Chapel Hill (T.C.W., S.P.S.); the Division of Pediatric Critical Care Medicine (E.H.M.) and the Department of Pediatrics (L.S.), Medical University of South Carolina, Charleston; the Division of Pediatric Infectious Diseases, Department of Pediatrics, Children's Mercy Kansas City, Kansas City, MO (J.E.S.); the Departments of Pediatrics and Microbiology, Division of Infectious Diseases, University of Mississippi Medical Center, Jackson (C.V.H.); the Department of Pediatrics, Division of Cardiology, Louisiana State University Health Sciences Center and Children's Hospital of New Orleans, New Orleans (T.T.B.); the Divisions of Pediatric Infectious Diseases and Pediatric Critical Care Medicine, Department of Pediatric and Adolescent Medicine, Mayo Clinic, Rochester (E.R.L.), and the Division of Pediatric Critical Care, University of Minnesota Masonic Children's Hospital, Minneapolis (J.R.H.) - both in Minnesota; the Division of Critical Care Medicine, Department of Anesthesiology and Critical Care, Children's Hospital of Philadelphia, Philadelphia (K.C.); the Ryan White Center for Pediatric Infectious Disease and Global Health, Department of Pediatrics, Indiana University School of Medicine, Indianapolis (S.S.B.); the Division of Pediatric Critical Care Medicine, Children's Hospital of Michigan, Central Michigan University, Detroit (S.M.H.), and the Division of Pediatric Critical Care Medicine, Department of Pediatrics, Mott Children's Hospital and University of Michigan, Ann Arbor (H.R.F.); the Division of Pediatric Critical Care, Department of Pediatrics, Children's Hospital and Medical Center, Omaha, NE (M.L.C.); the Division of Pediatric Critical Care, Department of Pediatrics, Cooperman Barnabas Medical Center, Livingston, NJ (S.J.G.); the Division of Critical Care Medicine, Department of Pediatrics, Northwestern University Feinberg School of Medicine, Ann and Robert H. Lurie Children's Hospital of Chicago, Chicago (B.M. Coates); the Division of Pediatric Critical Care Medicine, Department of Pediatrics, University of Alabama at Birmingham, Birmingham (M.K.); the Division of Pediatric Infectious Diseases, Department of Pediatrics, UHealth Holtz Children's Hospital, Miami (B.M. Chatani); and the Department of Pediatrics and Banner Children's at Diamond Children's Medical Center, University of Arizona, Tucson (K.V.T.).; Nofziger RA; From the Covid-19 Response Team, Centers for Disease Control and Prevention (A.M.P., S.M.O., M.W.T., L.D.Z., A.P.C., M.M.P.), the Center for Childhood Infections and Vaccines of Children's Healthcare of Atlanta and the Department of Pediatrics, Emory University School of Medicine (S.K.), and the Division of Critical Care Medicine, Department of Pediatrics, Emory University School of Medicine, Children's Healthcare of Atlanta (K.M.T.) - all in Atlanta; the Department of Anesthesiology, Critical Care, and Pain Medicine, Boston Children's Hospital (M.M.N., A.G.R.), and the Departments of Anaesthesia and Pediatrics, Harvard Medical School (A.G.R.) - both in Boston; the Division of Pediatric Infectious Diseases, Department of Pediatrics, Vanderbilt University Medical Center, Nashville (N.B.H.); the Department of Pediatrics, Baylor College of Medicine, Immunization Project, Texas Children's Hospital, Houston (J.A.B., L.C.S.), and the Department of Pediatrics, Division of Critical Care Medicine, University of Texas Southwestern, Children's Medical Center, Dallas (M.M.); the Division of Infectious Diseases, Children's Hospital Los Angeles and Departments of Pediatrics and Molecular Microbiology and Immunology, University of Southern California, Los Angeles (P.S.P.), the Division of Pediatric Hospital Medicine, UC San Diego-Rady Children's Hospital, San Diego (M.A.C.), the Division of Critical Care Medicine, UCSF Benioff Children's Hospital, Oakland (N.Z.C.), and the Department of Pediatrics, Divisions of Critical Care Medicine and Allergy, Immunology, and Bone Marrow Transplant, University of California, San Francisco, San Francisco (M.S.Z.) - all in California; Section of Pediatric Critical Care, Department of Pediatrics, Arkansas Children's Hospital, Little Rock (K.I.); the Division of Pediatric Critical Care Medicine, Nationwide Children's Hospital Columbus (K.E.B.), the Division of Critical Care Medicine, Department of Pediatrics, Akron Children's Hospital, Akron (R.A.N.), and the Department of Pediatrics, University of Cincinnati College of Medicine, Cincinnati Children's Hospital Medical Center, Cincinnati (M.A.S.) - all in Ohio; the Department of Pediatrics, Section of Critical Care Medicine, University of Colorado School of Medicine and Children's Hospital Colorado, Aurora (A.B.M.); the Department of Pediatrics, University of North Carolina at Chapel Hill Children's Hospital, Chapel Hill (T.C.W., S.P.S.); the Division of Pediatric Critical Care Medicine (E.H.M.) and the Department of Pediatrics (L.S.), Medical University of South Carolina, Charleston; the Division of Pediatric Infectious Diseases, Department of Pediatrics, Children's Mercy Kansas City, Kansas City, MO (J.E.S.); the Departments of Pediatrics and Microbiology, Division of Infectious Diseases, University of Mississippi Medical Center, Jackson (C.V.H.); the Department of Pediatrics, Division of Cardiology, Louisiana State University Health Sciences Center and Children's Hospital of New Orleans, New Orleans (T.T.B.); the Divisions of Pediatric Infectious Diseases and Pediatric Critical Care Medicine, Department of Pediatric and Adolescent Medicine, Mayo Clinic, Rochester (E.R.L.), and the Division of Pediatric Critical Care, University of Minnesota Masonic Children's Hospital, Minneapolis (J.R.H.) - both in Minnesota; the Division of Critical Care Medicine, Department of Anesthesiology and Critical Care, Children's Hospital of Philadelphia, Philadelphia (K.C.); the Ryan White Center for Pediatric Infectious Disease and Global Health, Department of Pediatrics, Indiana University School of Medicine, Indianapolis (S.S.B.); the Division of Pediatric Critical Care Medicine, Children's Hospital of Michigan, Central Michigan University, Detroit (S.M.H.), and the Division of Pediatric Critical Care Medicine, Department of Pediatrics, Mott Children's Hospital and University of Michigan, Ann Arbor (H.R.F.); the Division of Pediatric Critical Care, Department of Pediatrics, Children's Hospital and Medical Center, Omaha, NE (M.L.C.); the Division of Pediatric Critical Care, Department of Pediatrics, Cooperman Barnabas Medical Center, Livingston, NJ (S.J.G.); the Division of Critical Care Medicine, Department of Pediatrics, Northwestern University Feinberg School of Medicine, Ann and Robert H. Lurie Children's Hospital of Chicago, Chicago (B.M. Coates); the Division of Pediatric Critical Care Medicine, Department of Pediatrics, University of Alabama at Birmingham, Birmingham (M.K.); the Division of Pediatric Infectious Diseases, Department of Pediatrics, UHealth Holtz Children's Hospital, Miami (B.M. Chatani); and the Department of Pediatrics and Banner Children's at Diamond Children's Medical Center, University of Arizona, Tucson (K.V.T.).; Cameron MA; From the Covid-19 Response Team, Centers for Disease Control and Prevention (A.M.P., S.M.O., M.W.T., L.D.Z., A.P.C., M.M.P.), the Center for Childhood Infections and Vaccines of Children's Healthcare of Atlanta and the Department of Pediatrics, Emory University School of Medicine (S.K.), and the Division of Critical Care Medicine, Department of Pediatrics, Emory University School of Medicine, Children's Healthcare of Atlanta (K.M.T.) - all in Atlanta; the Department of Anesthesiology, Critical Care, and Pain Medicine, Boston Children's Hospital (M.M.N., A.G.R.), and the Departments of Anaesthesia and Pediatrics, Harvard Medical School (A.G.R.) - both in Boston; the Division of Pediatric Infectious Diseases, Department of Pediatrics, Vanderbilt University Medical Center, Nashville (N.B.H.); the Department of Pediatrics, Baylor College of Medicine, Immunization Project, Texas Children's Hospital, Houston (J.A.B., L.C.S.), and the Department of Pediatrics, Division of Critical Care Medicine, University of Texas Southwestern, Children's Medical Center, Dallas (M.M.); the Division of Infectious Diseases, Children's Hospital Los Angeles and Departments of Pediatrics and Molecular Microbiology and Immunology, University of Southern California, Los Angeles (P.S.P.), the Division of Pediatric Hospital Medicine, UC San Diego-Rady Children's Hospital, San Diego (M.A.C.), the Division of Critical Care Medicine, UCSF Benioff Children's Hospital, Oakland (N.Z.C.), and the Department of Pediatrics, Divisions of Critical Care Medicine and Allergy, Immunology, and Bone Marrow Transplant, University of California, San Francisco, San Francisco (M.S.Z.) - all in California; Section of Pediatric Critical Care, Department of Pediatrics, Arkansas Children's Hospital, Little Rock (K.I.); the Division of Pediatric Critical Care Medicine, Nationwide Children's Hospital Columbus (K.E.B.), the Division of Critical Care Medicine, Department of Pediatrics, Akron Children's Hospital, Akron (R.A.N.), and the Department of Pediatrics, University of Cincinnati College of Medicine, Cincinnati Children's Hospital Medical Center, Cincinnati (M.A.S.) - all in Ohio; the Department of Pediatrics, Section of Critical Care Medicine, University of Colorado School of Medicine and Children's Hospital Colorado, Aurora (A.B.M.); the Department of Pediatrics, University of North Carolina at Chapel Hill Children's Hospital, Chapel Hill (T.C.W., S.P.S.); the Division of Pediatric Critical Care Medicine (E.H.M.) and the Department of Pediatrics (L.S.), Medical University of South Carolina, Charleston; the Division of Pediatric Infectious Diseases, Department of Pediatrics, Children's Mercy Kansas City, Kansas City, MO (J.E.S.); the Departments of Pediatrics and Microbiology, Division of Infectious Diseases, University of Mississippi Medical Center, Jackson (C.V.H.); the Department of Pediatrics, Division of Cardiology, Louisiana State University Health Sciences Center and Children's Hospital of New Orleans, New Orleans (T.T.B.); the Divisions of Pediatric Infectious Diseases and Pediatric Critical Care Medicine, Department of Pediatric and Adolescent Medicine, Mayo Clinic, Rochester (E.R.L.), and the Division of Pediatric Critical Care, University of Minnesota Masonic Children's Hospital, Minneapolis (J.R.H.) - both in Minnesota; the Division of Critical Care Medicine, Department of Anesthesiology and Critical Care, Children's Hospital of Philadelphia, Philadelphia (K.C.); the Ryan White Center for Pediatric Infectious Disease and Global Health, Department of Pediatrics, Indiana University School of Medicine, Indianapolis (S.S.B.); the Division of Pediatric Critical Care Medicine, Children's Hospital of Michigan, Central Michigan University, Detroit (S.M.H.), and the Division of Pediatric Critical Care Medicine, Department of Pediatrics, Mott Children's Hospital and University of Michigan, Ann Arbor (H.R.F.); the Division of Pediatric Critical Care, Department of Pediatrics, Children's Hospital and Medical Center, Omaha, NE (M.L.C.); the Division of Pediatric Critical Care, Department of Pediatrics, Cooperman Barnabas Medical Center, Livingston, NJ (S.J.G.); the Division of Critical Care Medicine, Department of Pediatrics, Northwestern University Feinberg School of Medicine, Ann and Robert H. Lurie Children's Hospital of Chicago, Chicago (B.M. Coates); the Division of Pediatric Critical Care Medicine, Department of Pediatrics, University of Alabama at Birmingham, Birmingham (M.K.); the Division of Pediatric Infectious Diseases, Department of Pediatrics, UHealth Holtz Children's Hospital, Miami (B.M. Chatani); and the Department of Pediatrics and Banner Children's at Diamond Children's Medical Center, University of Arizona, Tucson (K.V.T.).; Walker TC; From the Covid-19 Response Team, Centers for Disease Control and Prevention (A.M.P., S.M.O., M.W.T., L.D.Z., A.P.C., M.M.P.), the Center for Childhood Infections and Vaccines of Children's Healthcare of Atlanta and the Department of Pediatrics, Emory University School of Medicine (S.K.), and the Division of Critical Care Medicine, Department of Pediatrics, Emory University School of Medicine, Children's Healthcare of Atlanta (K.M.T.) - all in Atlanta; the Department of Anesthesiology, Critical Care, and Pain Medicine, Boston Children's Hospital (M.M.N., A.G.R.), and the Departments of Anaesthesia and Pediatrics, Harvard Medical School (A.G.R.) - both in Boston; the Division of Pediatric Infectious Diseases, Department of Pediatrics, Vanderbilt University Medical Center, Nashville (N.B.H.); the Department of Pediatrics, Baylor College of Medicine, Immunization Project, Texas Children's Hospital, Houston (J.A.B., L.C.S.), and the Department of Pediatrics, Division of Critical Care Medicine, University of Texas Southwestern, Children's Medical Center, Dallas (M.M.); the Division of Infectious Diseases, Children's Hospital Los Angeles and Departments of Pediatrics and Molecular Microbiology and Immunology, University of Southern California, Los Angeles (P.S.P.), the Division of Pediatric Hospital Medicine, UC San Diego-Rady Children's Hospital, San Diego (M.A.C.), the Division of Critical Care Medicine, UCSF Benioff Children's Hospital, Oakland (N.Z.C.), and the Department of Pediatrics, Divisions of Critical Care Medicine and Allergy, Immunology, and Bone Marrow Transplant, University of California, San Francisco, San Francisco (M.S.Z.) - all in California; Section of Pediatric Critical Care, Department of Pediatrics, Arkansas Children's Hospital, Little Rock (K.I.); the Division of Pediatric Critical Care Medicine, Nationwide Children's Hospital Columbus (K.E.B.), the Division of Critical Care Medicine, Department of Pediatrics, Akron Children's Hospital, Akron (R.A.N.), and the Department of Pediatrics, University of Cincinnati College of Medicine, Cincinnati Children's Hospital Medical Center, Cincinnati (M.A.S.) - all in Ohio; the Department of Pediatrics, Section of Critical Care Medicine, University of Colorado School of Medicine and Children's Hospital Colorado, Aurora (A.B.M.); the Department of Pediatrics, University of North Carolina at Chapel Hill Children's Hospital, Chapel Hill (T.C.W., S.P.S.); the Division of Pediatric Critical Care Medicine (E.H.M.) and the Department of Pediatrics (L.S.), Medical University of South Carolina, Charleston; the Division of Pediatric Infectious Diseases, Department of Pediatrics, Children's Mercy Kansas City, Kansas City, MO (J.E.S.); the Departments of Pediatrics and Microbiology, Division of Infectious Diseases, University of Mississippi Medical Center, Jackson (C.V.H.); the Department of Pediatrics, Division of Cardiology, Louisiana State University Health Sciences Center and Children's Hospital of New Orleans, New Orleans (T.T.B.); the Divisions of Pediatric Infectious Diseases and Pediatric Critical Care Medicine, Department of Pediatric and Adolescent Medicine, Mayo Clinic, Rochester (E.R.L.), and the Division of Pediatric Critical Care, University of Minnesota Masonic Children's Hospital, Minneapolis (J.R.H.) - both in Minnesota; the Division of Critical Care Medicine, Department of Anesthesiology and Critical Care, Children's Hospital of Philadelphia, Philadelphia (K.C.); the Ryan White Center for Pediatric Infectious Disease and Global Health, Department of Pediatrics, Indiana University School of Medicine, Indianapolis (S.S.B.); the Division of Pediatric Critical Care Medicine, Children's Hospital of Michigan, Central Michigan University, Detroit (S.M.H.), and the Division of Pediatric Critical Care Medicine, Department of Pediatrics, Mott Children's Hospital and University of Michigan, Ann Arbor (H.R.F.); the Division of Pediatric Critical Care, Department of Pediatrics, Children's Hospital and Medical Center, Omaha, NE (M.L.C.); the Division of Pediatric Critical Care, Department of Pediatrics, Cooperman Barnabas Medical Center, Livingston, NJ (S.J.G.); the Division of Critical Care Medicine, Department of Pediatrics, Northwestern University Feinberg School of Medicine, Ann and Robert H. Lurie Children's Hospital of Chicago, Chicago (B.M. Coates); the Division of Pediatric Critical Care Medicine, Department of Pediatrics, University of Alabama at Birmingham, Birmingham (M.K.); the Division of Pediatric Infectious Diseases, Department of Pediatrics, UHealth Holtz Children's Hospital, Miami (B.M. Chatani); and the Department of Pediatrics and Banner Children's at Diamond Children's Medical Center, University of Arizona, Tucson (K.V.T.).; Schwartz SP; From the Covid-19 Response Team, Centers for Disease Control and Prevention (A.M.P., S.M.O., M.W.T., L.D.Z., A.P.C., M.M.P.), the Center for Childhood Infections and Vaccines of Children's Healthcare of Atlanta and the Department of Pediatrics, Emory University School of Medicine (S.K.), and the Division of Critical Care Medicine, Department of Pediatrics, Emory University School of Medicine, Children's Healthcare of Atlanta (K.M.T.) - all in Atlanta; the Department of Anesthesiology, Critical Care, and Pain Medicine, Boston Children's Hospital (M.M.N., A.G.R.), and the Departments of Anaesthesia and Pediatrics, Harvard Medical School (A.G.R.) - both in Boston; the Division of Pediatric Infectious Diseases, Department of Pediatrics, Vanderbilt University Medical Center, Nashville (N.B.H.); the Department of Pediatrics, Baylor College of Medicine, Immunization Project, Texas Children's Hospital, Houston (J.A.B., L.C.S.), and the Department of Pediatrics, Division of Critical Care Medicine, University of Texas Southwestern, Children's Medical Center, Dallas (M.M.); the Division of Infectious Diseases, Children's Hospital Los Angeles and Departments of Pediatrics and Molecular Microbiology and Immunology, University of Southern California, Los Angeles (P.S.P.), the Division of Pediatric Hospital Medicine, UC San Diego-Rady Children's Hospital, San Diego (M.A.C.), the Division of Critical Care Medicine, UCSF Benioff Children's Hospital, Oakland (N.Z.C.), and the Department of Pediatrics, Divisions of Critical Care Medicine and Allergy, Immunology, and Bone Marrow Transplant, University of California, San Francisco, San Francisco (M.S.Z.) - all in California; Section of Pediatric Critical Care, Department of Pediatrics, Arkansas Children's Hospital, Little Rock (K.I.); the Division of Pediatric Critical Care Medicine, Nationwide Children's Hospital Columbus (K.E.B.), the Division of Critical Care Medicine, Department of Pediatrics, Akron Children's Hospital, Akron (R.A.N.), and the Department of Pediatrics, University of Cincinnati College of Medicine, Cincinnati Children's Hospital Medical Center, Cincinnati (M.A.S.) - all in Ohio; the Department of Pediatrics, Section of Critical Care Medicine, University of Colorado School of Medicine and Children's Hospital Colorado, Aurora (A.B.M.); the Department of Pediatrics, University of North Carolina at Chapel Hill Children's Hospital, Chapel Hill (T.C.W., S.P.S.); the Division of Pediatric Critical Care Medicine (E.H.M.) and the Department of Pediatrics (L.S.), Medical University of South Carolina, Charleston; the Division of Pediatric Infectious Diseases, Department of Pediatrics, Children's Mercy Kansas City, Kansas City, MO (J.E.S.); the Departments of Pediatrics and Microbiology, Division of Infectious Diseases, University of Mississippi Medical Center, Jackson (C.V.H.); the Department of Pediatrics, Division of Cardiology, Louisiana State University Health Sciences Center and Children's Hospital of New Orleans, New Orleans (T.T.B.); the Divisions of Pediatric Infectious Diseases and Pediatric Critical Care Medicine, Department of Pediatric and Adolescent Medicine, Mayo Clinic, Rochester (E.R.L.), and the Division of Pediatric Critical Care, University of Minnesota Masonic Children's Hospital, Minneapolis (J.R.H.) - both in Minnesota; the Division of Critical Care Medicine, Department of Anesthesiology and Critical Care, Children's Hospital of Philadelphia, Philadelphia (K.C.); the Ryan White Center for Pediatric Infectious Disease and Global Health, Department of Pediatrics, Indiana University School of Medicine, Indianapolis (S.S.B.); the Division of Pediatric Critical Care Medicine, Children's Hospital of Michigan, Central Michigan University, Detroit (S.M.H.), and the Division of Pediatric Critical Care Medicine, Department of Pediatrics, Mott Children's Hospital and University of Michigan, Ann Arbor (H.R.F.); the Division of Pediatric Critical Care, Department of Pediatrics, Children's Hospital and Medical Center, Omaha, NE (M.L.C.); the Division of Pediatric Critical Care, Department of Pediatrics, Cooperman Barnabas Medical Center, Livingston, NJ (S.J.G.); the Division of Critical Care Medicine, Department of Pediatrics, Northwestern University Feinberg School of Medicine, Ann and Robert H. Lurie Children's Hospital of Chicago, Chicago (B.M. Coates); the Division of Pediatric Critical Care Medicine, Department of Pediatrics, University of Alabama at Birmingham, Birmingham (M.K.); the Division of Pediatric Infectious Diseases, Department of Pediatrics, UHealth Holtz Children's Hospital, Miami (B.M. Chatani); and the Department of Pediatrics and Banner Children's at Diamond Children's Medical Center, University of Arizona, Tucson (K.V.T.).; Mack EH; From the Covid-19 Response Team, Centers for Disease Control and Prevention (A.M.P., S.M.O., M.W.T., L.D.Z., A.P.C., M.M.P.), the Center for Childhood Infections and Vaccines of Children's Healthcare of Atlanta and the Department of Pediatrics, Emory University School of Medicine (S.K.), and the Division of Critical Care Medicine, Department of Pediatrics, Emory University School of Medicine, Children's Healthcare of Atlanta (K.M.T.) - all in Atlanta; the Department of Anesthesiology, Critical Care, and Pain Medicine, Boston Children's Hospital (M.M.N., A.G.R.), and the Departments of Anaesthesia and Pediatrics, Harvard Medical School (A.G.R.) - both in Boston; the Division of Pediatric Infectious Diseases, Department of Pediatrics, Vanderbilt University Medical Center, Nashville (N.B.H.); the Department of Pediatrics, Baylor College of Medicine, Immunization Project, Texas Children's Hospital, Houston (J.A.B., L.C.S.), and the Department of Pediatrics, Division of Critical Care Medicine, University of Texas Southwestern, Children's Medical Center, Dallas (M.M.); the Division of Infectious Diseases, Children's Hospital Los Angeles and Departments of Pediatrics and Molecular Microbiology and Immunology, University of Southern California, Los Angeles (P.S.P.), the Division of Pediatric Hospital Medicine, UC San Diego-Rady Children's Hospital, San Diego (M.A.C.), the Division of Critical Care Medicine, UCSF Benioff Children's Hospital, Oakland (N.Z.C.), and the Department of Pediatrics, Divisions of Critical Care Medicine and Allergy, Immunology, and Bone Marrow Transplant, University of California, San Francisco, San Francisco (M.S.Z.) - all in California; Section of Pediatric Critical Care, Department of Pediatrics, Arkansas Children's Hospital, Little Rock (K.I.); the Division of Pediatric Critical Care Medicine, Nationwide Children's Hospital Columbus (K.E.B.), the Division of Critical Care Medicine, Department of Pediatrics, Akron Children's Hospital, Akron (R.A.N.), and the Department of Pediatrics, University of Cincinnati College of Medicine, Cincinnati Children's Hospital Medical Center, Cincinnati (M.A.S.) - all in Ohio; the Department of Pediatrics, Section of Critical Care Medicine, University of Colorado School of Medicine and Children's Hospital Colorado, Aurora (A.B.M.); the Department of Pediatrics, University of North Carolina at Chapel Hill Children's Hospital, Chapel Hill (T.C.W., S.P.S.); the Division of Pediatric Critical Care Medicine (E.H.M.) and the Department of Pediatrics (L.S.), Medical University of South Carolina, Charleston; the Division of Pediatric Infectious Diseases, Department of Pediatrics, Children's Mercy Kansas City, Kansas City, MO (J.E.S.); the Departments of Pediatrics and Microbiology, Division of Infectious Diseases, University of Mississippi Medical Center, Jackson (C.V.H.); the Department of Pediatrics, Division of Cardiology, Louisiana State University Health Sciences Center and Children's Hospital of New Orleans, New Orleans (T.T.B.); the Divisions of Pediatric Infectious Diseases and Pediatric Critical Care Medicine, Department of Pediatric and Adolescent Medicine, Mayo Clinic, Rochester (E.R.L.), and the Division of Pediatric Critical Care, University of Minnesota Masonic Children's Hospital, Minneapolis (J.R.H.) - both in Minnesota; the Division of Critical Care Medicine, Department of Anesthesiology and Critical Care, Children's Hospital of Philadelphia, Philadelphia (K.C.); the Ryan White Center for Pediatric Infectious Disease and Global Health, Department of Pediatrics, Indiana University School of Medicine, Indianapolis (S.S.B.); the Division of Pediatric Critical Care Medicine, Children's Hospital of Michigan, Central Michigan University, Detroit (S.M.H.), and the Division of Pediatric Critical Care Medicine, Department of Pediatrics, Mott Children's Hospital and University of Michigan, Ann Arbor (H.R.F.); the Division of Pediatric Critical Care, Department of Pediatrics, Children's Hospital and Medical Center, Omaha, NE (M.L.C.); the Division of Pediatric Critical Care, Department of Pediatrics, Cooperman Barnabas Medical Center, Livingston, NJ (S.J.G.); the Division of Critical Care Medicine, Department of Pediatrics, Northwestern University Feinberg School of Medicine, Ann and Robert H. Lurie Children's Hospital of Chicago, Chicago (B.M. Coates); the Division of Pediatric Critical Care Medicine, Department of Pediatrics, University of Alabama at Birmingham, Birmingham (M.K.); the Division of Pediatric Infectious Diseases, Department of Pediatrics, UHealth Holtz Children's Hospital, Miami (B.M. Chatani); and the Department of Pediatrics and Banner Children's at Diamond Children's Medical Center, University of Arizona, Tucson (K.V.T.).; Smallcomb L; From the Covid-19 Response Team, Centers for Disease Control and Prevention (A.M.P., S.M.O., M.W.T., L.D.Z., A.P.C., M.M.P.), the Center for Childhood Infections and Vaccines of Children's Healthcare of Atlanta and the Department of Pediatrics, Emory University School of Medicine (S.K.), and the Division of Critical Care Medicine, Department of Pediatrics, Emory University School of Medicine, Children's Healthcare of Atlanta (K.M.T.) - all in Atlanta; the Department of Anesthesiology, Critical Care, and Pain Medicine, Boston Children's Hospital (M.M.N., A.G.R.), and the Departments of Anaesthesia and Pediatrics, Harvard Medical School (A.G.R.) - both in Boston; the Division of Pediatric Infectious Diseases, Department of Pediatrics, Vanderbilt University Medical Center, Nashville (N.B.H.); the Department of Pediatrics, Baylor College of Medicine, Immunization Project, Texas Children's Hospital, Houston (J.A.B., L.C.S.), and the Department of Pediatrics, Division of Critical Care Medicine, University of Texas Southwestern, Children's Medical Center, Dallas (M.M.); the Division of Infectious Diseases, Children's Hospital Los Angeles and Departments of Pediatrics and Molecular Microbiology and Immunology, University of Southern California, Los Angeles (P.S.P.), the Division of Pediatric Hospital Medicine, UC San Diego-Rady Children's Hospital, San Diego (M.A.C.), the Division of Critical Care Medicine, UCSF Benioff Children's Hospital, Oakland (N.Z.C.), and the Department of Pediatrics, Divisions of Critical Care Medicine and Allergy, Immunology, and Bone Marrow Transplant, University of California, San Francisco, San Francisco (M.S.Z.) - all in California; Section of Pediatric Critical Care, Department of Pediatrics, Arkansas Children's Hospital, Little Rock (K.I.); the Division of Pediatric Critical Care Medicine, Nationwide Children's Hospital Columbus (K.E.B.), the Division of Critical Care Medicine, Department of Pediatrics, Akron Children's Hospital, Akron (R.A.N.), and the Department of Pediatrics, University of Cincinnati College of Medicine, Cincinnati Children's Hospital Medical Center, Cincinnati (M.A.S.) - all in Ohio; the Department of Pediatrics, Section of Critical Care Medicine, University of Colorado School of Medicine and Children's Hospital Colorado, Aurora (A.B.M.); the Department of Pediatrics, University of North Carolina at Chapel Hill Children's Hospital, Chapel Hill (T.C.W., S.P.S.); the Division of Pediatric Critical Care Medicine (E.H.M.) and the Department of Pediatrics (L.S.), Medical University of South Carolina, Charleston; the Division of Pediatric Infectious Diseases, Department of Pediatrics, Children's Mercy Kansas City, Kansas City, MO (J.E.S.); the Departments of Pediatrics and Microbiology, Division of Infectious Diseases, University of Mississippi Medical Center, Jackson (C.V.H.); the Department of Pediatrics, Division of Cardiology, Louisiana State University Health Sciences Center and Children's Hospital of New Orleans, New Orleans (T.T.B.); the Divisions of Pediatric Infectious Diseases and Pediatric Critical Care Medicine, Department of Pediatric and Adolescent Medicine, Mayo Clinic, Rochester (E.R.L.), and the Division of Pediatric Critical Care, University of Minnesota Masonic Children's Hospital, Minneapolis (J.R.H.) - both in Minnesota; the Division of Critical Care Medicine, Department of Anesthesiology and Critical Care, Children's Hospital of Philadelphia, Philadelphia (K.C.); the Ryan White Center for Pediatric Infectious Disease and Global Health, Department of Pediatrics, Indiana University School of Medicine, Indianapolis (S.S.B.); the Division of Pediatric Critical Care Medicine, Children's Hospital of Michigan, Central Michigan University, Detroit (S.M.H.), and the Division of Pediatric Critical Care Medicine, Department of Pediatrics, Mott Children's Hospital and University of Michigan, Ann Arbor (H.R.F.); the Division of Pediatric Critical Care, Department of Pediatrics, Children's Hospital and Medical Center, Omaha, NE (M.L.C.); the Division of Pediatric Critical Care, Department of Pediatrics, Cooperman Barnabas Medical Center, Livingston, NJ (S.J.G.); the Division of Critical Care Medicine, Department of Pediatrics, Northwestern University Feinberg School of Medicine, Ann and Robert H. Lurie Children's Hospital of Chicago, Chicago (B.M. Coates); the Division of Pediatric Critical Care Medicine, Department of Pediatrics, University of Alabama at Birmingham, Birmingham (M.K.); the Division of Pediatric Infectious Diseases, Department of Pediatrics, UHealth Holtz Children's Hospital, Miami (B.M. Chatani); and the Department of Pediatrics and Banner Children's at Diamond Children's Medical Center, University of Arizona, Tucson (K.V.T.).; Schuster JE; From the Covid-19 Response Team, Centers for Disease Control and Prevention (A.M.P., S.M.O., M.W.T., L.D.Z., A.P.C., M.M.P.), the Center for Childhood Infections and Vaccines of Children's Healthcare of Atlanta and the Department of Pediatrics, Emory University School of Medicine (S.K.), and the Division of Critical Care Medicine, Department of Pediatrics, Emory University School of Medicine, Children's Healthcare of Atlanta (K.M.T.) - all in Atlanta; the Department of Anesthesiology, Critical Care, and Pain Medicine, Boston Children's Hospital (M.M.N., A.G.R.), and the Departments of Anaesthesia and Pediatrics, Harvard Medical School (A.G.R.) - both in Boston; the Division of Pediatric Infectious Diseases, Department of Pediatrics, Vanderbilt University Medical Center, Nashville (N.B.H.); the Department of Pediatrics, Baylor College of Medicine, Immunization Project, Texas Children's Hospital, Houston (J.A.B., L.C.S.), and the Department of Pediatrics, Division of Critical Care Medicine, University of Texas Southwestern, Children's Medical Center, Dallas (M.M.); the Division of Infectious Diseases, Children's Hospital Los Angeles and Departments of Pediatrics and Molecular Microbiology and Immunology, University of Southern California, Los Angeles (P.S.P.), the Division of Pediatric Hospital Medicine, UC San Diego-Rady Children's Hospital, San Diego (M.A.C.), the Division of Critical Care Medicine, UCSF Benioff Children's Hospital, Oakland (N.Z.C.), and the Department of Pediatrics, Divisions of Critical Care Medicine and Allergy, Immunology, and Bone Marrow Transplant, University of California, San Francisco, San Francisco (M.S.Z.) - all in California; Section of Pediatric Critical Care, Department of Pediatrics, Arkansas Children's Hospital, Little Rock (K.I.); the Division of Pediatric Critical Care Medicine, Nationwide Children's Hospital Columbus (K.E.B.), the Division of Critical Care Medicine, Department of Pediatrics, Akron Children's Hospital, Akron (R.A.N.), and the Department of Pediatrics, University of Cincinnati College of Medicine, Cincinnati Children's Hospital Medical Center, Cincinnati (M.A.S.) - all in Ohio; the Department of Pediatrics, Section of Critical Care Medicine, University of Colorado School of Medicine and Children's Hospital Colorado, Aurora (A.B.M.); the Department of Pediatrics, University of North Carolina at Chapel Hill Children's Hospital, Chapel Hill (T.C.W., S.P.S.); the Division of Pediatric Critical Care Medicine (E.H.M.) and the Department of Pediatrics (L.S.), Medical University of South Carolina, Charleston; the Division of Pediatric Infectious Diseases, Department of Pediatrics, Children's Mercy Kansas City, Kansas City, MO (J.E.S.); the Departments of Pediatrics and Microbiology, Division of Infectious Diseases, University of Mississippi Medical Center, Jackson (C.V.H.); the Department of Pediatrics, Division of Cardiology, Louisiana State University Health Sciences Center and Children's Hospital of New Orleans, New Orleans (T.T.B.); the Divisions of Pediatric Infectious Diseases and Pediatric Critical Care Medicine, Department of Pediatric and Adolescent Medicine, Mayo Clinic, Rochester (E.R.L.), and the Division of Pediatric Critical Care, University of Minnesota Masonic Children's Hospital, Minneapolis (J.R.H.) - both in Minnesota; the Division of Critical Care Medicine, Department of Anesthesiology and Critical Care, Children's Hospital of Philadelphia, Philadelphia (K.C.); the Ryan White Center for Pediatric Infectious Disease and Global Health, Department of Pediatrics, Indiana University School of Medicine, Indianapolis (S.S.B.); the Division of Pediatric Critical Care Medicine, Children's Hospital of Michigan, Central Michigan University, Detroit (S.M.H.), and the Division of Pediatric Critical Care Medicine, Department of Pediatrics, Mott Children's Hospital and University of Michigan, Ann Arbor (H.R.F.); the Division of Pediatric Critical Care, Department of Pediatrics, Children's Hospital and Medical Center, Omaha, NE (M.L.C.); the Division of Pediatric Critical Care, Department of Pediatrics, Cooperman Barnabas Medical Center, Livingston, NJ (S.J.G.); the Division of Critical Care Medicine, Department of Pediatrics, Northwestern University Feinberg School of Medicine, Ann and Robert H. Lurie Children's Hospital of Chicago, Chicago (B.M. Coates); the Division of Pediatric Critical Care Medicine, Department of Pediatrics, University of Alabama at Birmingham, Birmingham (M.K.); the Division of Pediatric Infectious Diseases, Department of Pediatrics, UHealth Holtz Children's Hospital, Miami (B.M. Chatani); and the Department of Pediatrics and Banner Children's at Diamond Children's Medical Center, University of Arizona, Tucson (K.V.T.).; Hobbs CV; From the Covid-19 Response Team, Centers for Disease Control and Prevention (A.M.P., S.M.O., M.W.T., L.D.Z., A.P.C., M.M.P.), the Center for Childhood Infections and Vaccines of Children's Healthcare of Atlanta and the Department of Pediatrics, Emory University School of Medicine (S.K.), and the Division of Critical Care Medicine, Department of Pediatrics, Emory University School of Medicine, Children's Healthcare of Atlanta (K.M.T.) - all in Atlanta; the Department of Anesthesiology, Critical Care, and Pain Medicine, Boston Children's Hospital (M.M.N., A.G.R.), and the Departments of Anaesthesia and Pediatrics, Harvard Medical School (A.G.R.) - both in Boston; the Division of Pediatric Infectious Diseases, Department of Pediatrics, Vanderbilt University Medical Center, Nashville (N.B.H.); the Department of Pediatrics, Baylor College of Medicine, Immunization Project, Texas Children's Hospital, Houston (J.A.B., L.C.S.), and the Department of Pediatrics, Division of Critical Care Medicine, University of Texas Southwestern, Children's Medical Center, Dallas (M.M.); the Division of Infectious Diseases, Children's Hospital Los Angeles and Departments of Pediatrics and Molecular Microbiology and Immunology, University of Southern California, Los Angeles (P.S.P.), the Division of Pediatric Hospital Medicine, UC San Diego-Rady Children's Hospital, San Diego (M.A.C.), the Division of Critical Care Medicine, UCSF Benioff Children's Hospital, Oakland (N.Z.C.), and the Department of Pediatrics, Divisions of Critical Care Medicine and Allergy, Immunology, and Bone Marrow Transplant, University of California, San Francisco, San Francisco (M.S.Z.) - all in California; Section of Pediatric Critical Care, Department of Pediatrics, Arkansas Children's Hospital, Little Rock (K.I.); the Division of Pediatric Critical Care Medicine, Nationwide Children's Hospital Columbus (K.E.B.), the Division of Critical Care Medicine, Department of Pediatrics, Akron Children's Hospital, Akron (R.A.N.), and the Department of Pediatrics, University of Cincinnati College of Medicine, Cincinnati Children's Hospital Medical Center, Cincinnati (M.A.S.) - all in Ohio; the Department of Pediatrics, Section of Critical Care Medicine, University of Colorado School of Medicine and Children's Hospital Colorado, Aurora (A.B.M.); the Department of Pediatrics, University of North Carolina at Chapel Hill Children's Hospital, Chapel Hill (T.C.W., S.P.S.); the Division of Pediatric Critical Care Medicine (E.H.M.) and the Department of Pediatrics (L.S.), Medical University of South Carolina, Charleston; the Division of Pediatric Infectious Diseases, Department of Pediatrics, Children's Mercy Kansas City, Kansas City, MO (J.E.S.); the Departments of Pediatrics and Microbiology, Division of Infectious Diseases, University of Mississippi Medical Center, Jackson (C.V.H.); the Department of Pediatrics, Division of Cardiology, Louisiana State University Health Sciences Center and Children's Hospital of New Orleans, New Orleans (T.T.B.); the Divisions of Pediatric Infectious Diseases and Pediatric Critical Care Medicine, Department of Pediatric and Adolescent Medicine, Mayo Clinic, Rochester (E.R.L.), and the Division of Pediatric Critical Care, University of Minnesota Masonic Children's Hospital, Minneapolis (J.R.H.) - both in Minnesota; the Division of Critical Care Medicine, Department of Anesthesiology and Critical Care, Children's Hospital of Philadelphia, Philadelphia (K.C.); the Ryan White Center for Pediatric Infectious Disease and Global Health, Department of Pediatrics, Indiana University School of Medicine, Indianapolis (S.S.B.); the Division of Pediatric Critical Care Medicine, Children's Hospital of Michigan, Central Michigan University, Detroit (S.M.H.), and the Division of Pediatric Critical Care Medicine, Department of Pediatrics, Mott Children's Hospital and University of Michigan, Ann Arbor (H.R.F.); the Division of Pediatric Critical Care, Department of Pediatrics, Children's Hospital and Medical Center, Omaha, NE (M.L.C.); the Division of Pediatric Critical Care, Department of Pediatrics, Cooperman Barnabas Medical Center, Livingston, NJ (S.J.G.); the Division of Critical Care Medicine, Department of Pediatrics, Northwestern University Feinberg School of Medicine, Ann and Robert H. Lurie Children's Hospital of Chicago, Chicago (B.M. Coates); the Division of Pediatric Critical Care Medicine, Department of Pediatrics, University of Alabama at Birmingham, Birmingham (M.K.); the Division of Pediatric Infectious Diseases, Department of Pediatrics, UHealth Holtz Children's Hospital, Miami (B.M. Chatani); and the Department of Pediatrics and Banner Children's at Diamond Children's Medical Center, University of Arizona, Tucson (K.V.T.).; Kamidani S; From the Covid-19 Response Team, Centers for Disease Control and Prevention (A.M.P., S.M.O., M.W.T., L.D.Z., A.P.C., M.M.P.), the Center for Childhood Infections and Vaccines of Children's Healthcare of Atlanta and the Department of Pediatrics, Emory University School of Medicine (S.K.), and the Division of Critical Care Medicine, Department of Pediatrics, Emory University School of Medicine, Children's Healthcare of Atlanta (K.M.T.) - all in Atlanta; the Department of Anesthesiology, Critical Care, and Pain Medicine, Boston Children's Hospital (M.M.N., A.G.R.), and the Departments of Anaesthesia and Pediatrics, Harvard Medical School (A.G.R.) - both in Boston; the Division of Pediatric Infectious Diseases, Department of Pediatrics, Vanderbilt University Medical Center, Nashville (N.B.H.); the Department of Pediatrics, Baylor College of Medicine, Immunization Project, Texas Children's Hospital, Houston (J.A.B., L.C.S.), and the Department of Pediatrics, Division of Critical Care Medicine, University of Texas Southwestern, Children's Medical Center, Dallas (M.M.); the Division of Infectious Diseases, Children's Hospital Los Angeles and Departments of Pediatrics and Molecular Microbiology and Immunology, University of Southern California, Los Angeles (P.S.P.), the Division of Pediatric Hospital Medicine, UC San Diego-Rady Children's Hospital, San Diego (M.A.C.), the Division of Critical Care Medicine, UCSF Benioff Children's Hospital, Oakland (N.Z.C.), and the Department of Pediatrics, Divisions of Critical Care Medicine and Allergy, Immunology, and Bone Marrow Transplant, University of California, San Francisco, San Francisco (M.S.Z.) - all in California; Section of Pediatric Critical Care, Department of Pediatrics, Arkansas Children's Hospital, Little Rock (K.I.); the Division of Pediatric Critical Care Medicine, Nationwide Children's Hospital Columbus (K.E.B.), the Division of Critical Care Medicine, Department of Pediatrics, Akron Children's Hospital, Akron (R.A.N.), and the Department of Pediatrics, University of Cincinnati College of Medicine, Cincinnati Children's Hospital Medical Center, Cincinnati (M.A.S.) - all in Ohio; the Department of Pediatrics, Section of Critical Care Medicine, University of Colorado School of Medicine and Children's Hospital Colorado, Aurora (A.B.M.); the Department of Pediatrics, University of North Carolina at Chapel Hill Children's Hospital, Chapel Hill (T.C.W., S.P.S.); the Division of Pediatric Critical Care Medicine (E.H.M.) and the Department of Pediatrics (L.S.), Medical University of South Carolina, Charleston; the Division of Pediatric Infectious Diseases, Department of Pediatrics, Children's Mercy Kansas City, Kansas City, MO (J.E.S.); the Departments of Pediatrics and Microbiology, Division of Infectious Diseases, University of Mississippi Medical Center, Jackson (C.V.H.); the Department of Pediatrics, Division of Cardiology, Louisiana State University Health Sciences Center and Children's Hospital of New Orleans, New Orleans (T.T.B.); the Divisions of Pediatric Infectious Diseases and Pediatric Critical Care Medicine, Department of Pediatric and Adolescent Medicine, Mayo Clinic, Rochester (E.R.L.), and the Division of Pediatric Critical Care, University of Minnesota Masonic Children's Hospital, Minneapolis (J.R.H.) - both in Minnesota; the Division of Critical Care Medicine, Department of Anesthesiology and Critical Care, Children's Hospital of Philadelphia, Philadelphia (K.C.); the Ryan White Center for Pediatric Infectious Disease and Global Health, Department of Pediatrics, Indiana University School of Medicine, Indianapolis (S.S.B.); the Division of Pediatric Critical Care Medicine, Children's Hospital of Michigan, Central Michigan University, Detroit (S.M.H.), and the Division of Pediatric Critical Care Medicine, Department of Pediatrics, Mott Children's Hospital and University of Michigan, Ann Arbor (H.R.F.); the Division of Pediatric Critical Care, Department of Pediatrics, Children's Hospital and Medical Center, Omaha, NE (M.L.C.); the Division of Pediatric Critical Care, Department of Pediatrics, Cooperman Barnabas Medical Center, Livingston, NJ (S.J.G.); the Division of Critical Care Medicine, Department of Pediatrics, Northwestern University Feinberg School of Medicine, Ann and Robert H. Lurie Children's Hospital of Chicago, Chicago (B.M. Coates); the Division of Pediatric Critical Care Medicine, Department of Pediatrics, University of Alabama at Birmingham, Birmingham (M.K.); the Division of Pediatric Infectious Diseases, Department of Pediatrics, UHealth Holtz Children's Hospital, Miami (B.M. Chatani); and the Department of Pediatrics and Banner Children's at Diamond Children's Medical Center, University of Arizona, Tucson (K.V.T.).; Tarquinio KM; From the Covid-19 Response Team, Centers for Disease Control and Prevention (A.M.P., S.M.O., M.W.T., L.D.Z., A.P.C., M.M.P.), the Center for Childhood Infections and Vaccines of Children's Healthcare of Atlanta and the Department of Pediatrics, Emory University School of Medicine (S.K.), and the Division of Critical Care Medicine, Department of Pediatrics, Emory University School of Medicine, Children's Healthcare of Atlanta (K.M.T.) - all in Atlanta; the Department of Anesthesiology, Critical Care, and Pain Medicine, Boston Children's Hospital (M.M.N., A.G.R.), and the Departments of Anaesthesia and Pediatrics, Harvard Medical School (A.G.R.) - both in Boston; the Division of Pediatric Infectious Diseases, Department of Pediatrics, Vanderbilt University Medical Center, Nashville (N.B.H.); the Department of Pediatrics, Baylor College of Medicine, Immunization Project, Texas Children's Hospital, Houston (J.A.B., L.C.S.), and the Department of Pediatrics, Division of Critical Care Medicine, University of Texas Southwestern, Children's Medical Center, Dallas (M.M.); the Division of Infectious Diseases, Children's Hospital Los Angeles and Departments of Pediatrics and Molecular Microbiology and Immunology, University of Southern California, Los Angeles (P.S.P.), the Division of Pediatric Hospital Medicine, UC San Diego-Rady Children's Hospital, San Diego (M.A.C.), the Division of Critical Care Medicine, UCSF Benioff Children's Hospital, Oakland (N.Z.C.), and the Department of Pediatrics, Divisions of Critical Care Medicine and Allergy, Immunology, and Bone Marrow Transplant, University of California, San Francisco, San Francisco (M.S.Z.) - all in California; Section of Pediatric Critical Care, Department of Pediatrics, Arkansas Children's Hospital, Little Rock (K.I.); the Division of Pediatric Critical Care Medicine, Nationwide Children's Hospital Columbus (K.E.B.), the Division of Critical Care Medicine, Department of Pediatrics, Akron Children's Hospital, Akron (R.A.N.), and the Department of Pediatrics, University of Cincinnati College of Medicine, Cincinnati Children's Hospital Medical Center, Cincinnati (M.A.S.) - all in Ohio; the Department of Pediatrics, Section of Critical Care Medicine, University of Colorado School of Medicine and Children's Hospital Colorado, Aurora (A.B.M.); the Department of Pediatrics, University of North Carolina at Chapel Hill Children's Hospital, Chapel Hill (T.C.W., S.P.S.); the Division of Pediatric Critical Care Medicine (E.H.M.) and the Department of Pediatrics (L.S.), Medical University of South Carolina, Charleston; the Division of Pediatric Infectious Diseases, Department of Pediatrics, Children's Mercy Kansas City, Kansas City, MO (J.E.S.); the Departments of Pediatrics and Microbiology, Division of Infectious Diseases, University of Mississippi Medical Center, Jackson (C.V.H.); the Department of Pediatrics, Division of Cardiology, Louisiana State University Health Sciences Center and Children's Hospital of New Orleans, New Orleans (T.T.B.); the Divisions of Pediatric Infectious Diseases and Pediatric Critical Care Medicine, Department of Pediatric and Adolescent Medicine, Mayo Clinic, Rochester (E.R.L.), and the Division of Pediatric Critical Care, University of Minnesota Masonic Children's Hospital, Minneapolis (J.R.H.) - both in Minnesota; the Division of Critical Care Medicine, Department of Anesthesiology and Critical Care, Children's Hospital of Philadelphia, Philadelphia (K.C.); the Ryan White Center for Pediatric Infectious Disease and Global Health, Department of Pediatrics, Indiana University School of Medicine, Indianapolis (S.S.B.); the Division of Pediatric Critical Care Medicine, Children's Hospital of Michigan, Central Michigan University, Detroit (S.M.H.), and the Division of Pediatric Critical Care Medicine, Department of Pediatrics, Mott Children's Hospital and University of Michigan, Ann Arbor (H.R.F.); the Division of Pediatric Critical Care, Department of Pediatrics, Children's Hospital and Medical Center, Omaha, NE (M.L.C.); the Division of Pediatric Critical Care, Department of Pediatrics, Cooperman Barnabas Medical Center, Livingston, NJ (S.J.G.); the Division of Critical Care Medicine, Department of Pediatrics, Northwestern University Feinberg School of Medicine, Ann and Robert H. Lurie Children's Hospital of Chicago, Chicago (B.M. Coates); the Division of Pediatric Critical Care Medicine, Department of Pediatrics, University of Alabama at Birmingham, Birmingham (M.K.); the Division of Pediatric Infectious Diseases, Department of Pediatrics, UHealth Holtz Children's Hospital, Miami (B.M. Chatani); and the Department of Pediatrics and Banner Children's at Diamond Children's Medical Center, University of Arizona, Tucson (K.V.T.).; Bradford TT; From the Covid-19 Response Team, Centers for Disease Control and Prevention (A.M.P., S.M.O., M.W.T., L.D.Z., A.P.C., M.M.P.), the Center for Childhood Infections and Vaccines of Children's Healthcare of Atlanta and the Department of Pediatrics, Emory University School of Medicine (S.K.), and the Division of Critical Care Medicine, Department of Pediatrics, Emory University School of Medicine, Children's Healthcare of Atlanta (K.M.T.) - all in Atlanta; the Department of Anesthesiology, Critical Care, and Pain Medicine, Boston Children's Hospital (M.M.N., A.G.R.), and the Departments of Anaesthesia and Pediatrics, Harvard Medical School (A.G.R.) - both in Boston; the Division of Pediatric Infectious Diseases, Department of Pediatrics, Vanderbilt University Medical Center, Nashville (N.B.H.); the Department of Pediatrics, Baylor College of Medicine, Immunization Project, Texas Children's Hospital, Houston (J.A.B., L.C.S.), and the Department of Pediatrics, Division of Critical Care Medicine, University of Texas Southwestern, Children's Medical Center, Dallas (M.M.); the Division of Infectious Diseases, Children's Hospital Los Angeles and Departments of Pediatrics and Molecular Microbiology and Immunology, University of Southern California, Los Angeles (P.S.P.), the Division of Pediatric Hospital Medicine, UC San Diego-Rady Children's Hospital, San Diego (M.A.C.), the Division of Critical Care Medicine, UCSF Benioff Children's Hospital, Oakland (N.Z.C.), and the Department of Pediatrics, Divisions of Critical Care Medicine and Allergy, Immunology, and Bone Marrow Transplant, University of California, San Francisco, San Francisco (M.S.Z.) - all in California; Section of Pediatric Critical Care, Department of Pediatrics, Arkansas Children's Hospital, Little Rock (K.I.); the Division of Pediatric Critical Care Medicine, Nationwide Children's Hospital Columbus (K.E.B.), the Division of Critical Care Medicine, Department of Pediatrics, Akron Children's Hospital, Akron (R.A.N.), and the Department of Pediatrics, University of Cincinnati College of Medicine, Cincinnati Children's Hospital Medical Center, Cincinnati (M.A.S.) - all in Ohio; the Department of Pediatrics, Section of Critical Care Medicine, University of Colorado School of Medicine and Children's Hospital Colorado, Aurora (A.B.M.); the Department of Pediatrics, University of North Carolina at Chapel Hill Children's Hospital, Chapel Hill (T.C.W., S.P.S.); the Division of Pediatric Critical Care Medicine (E.H.M.) and the Department of Pediatrics (L.S.), Medical University of South Carolina, Charleston; the Division of Pediatric Infectious Diseases, Department of Pediatrics, Children's Mercy Kansas City, Kansas City, MO (J.E.S.); the Departments of Pediatrics and Microbiology, Division of Infectious Diseases, University of Mississippi Medical Center, Jackson (C.V.H.); the Department of Pediatrics, Division of Cardiology, Louisiana State University Health Sciences Center and Children's Hospital of New Orleans, New Orleans (T.T.B.); the Divisions of Pediatric Infectious Diseases and Pediatric Critical Care Medicine, Department of Pediatric and Adolescent Medicine, Mayo Clinic, Rochester (E.R.L.), and the Division of Pediatric Critical Care, University of Minnesota Masonic Children's Hospital, Minneapolis (J.R.H.) - both in Minnesota; the Division of Critical Care Medicine, Department of Anesthesiology and Critical Care, Children's Hospital of Philadelphia, Philadelphia (K.C.); the Ryan White Center for Pediatric Infectious Disease and Global Health, Department of Pediatrics, Indiana University School of Medicine, Indianapolis (S.S.B.); the Division of Pediatric Critical Care Medicine, Children's Hospital of Michigan, Central Michigan University, Detroit (S.M.H.), and the Division of Pediatric Critical Care Medicine, Department of Pediatrics, Mott Children's Hospital and University of Michigan, Ann Arbor (H.R.F.); the Division of Pediatric Critical Care, Department of Pediatrics, Children's Hospital and Medical Center, Omaha, NE (M.L.C.); the Division of Pediatric Critical Care, Department of Pediatrics, Cooperman Barnabas Medical Center, Livingston, NJ (S.J.G.); the Division of Critical Care Medicine, Department of Pediatrics, Northwestern University Feinberg School of Medicine, Ann and Robert H. Lurie Children's Hospital of Chicago, Chicago (B.M. Coates); the Division of Pediatric Critical Care Medicine, Department of Pediatrics, University of Alabama at Birmingham, Birmingham (M.K.); the Division of Pediatric Infectious Diseases, Department of Pediatrics, UHealth Holtz Children's Hospital, Miami (B.M. Chatani); and the Department of Pediatrics and Banner Children's at Diamond Children's Medical Center, University of Arizona, Tucson (K.V.T.).; Levy ER; From the Covid-19 Response Team, Centers for Disease Control and Prevention (A.M.P., S.M.O., M.W.T., L.D.Z., A.P.C., M.M.P.), the Center for Childhood Infections and Vaccines of Children's Healthcare of Atlanta and the Department of Pediatrics, Emory University School of Medicine (S.K.), and the Division of Critical Care Medicine, Department of Pediatrics, Emory University School of Medicine, Children's Healthcare of Atlanta (K.M.T.) - all in Atlanta; the Department of Anesthesiology, Critical Care, and Pain Medicine, Boston Children's Hospital (M.M.N., A.G.R.), and the Departments of Anaesthesia and Pediatrics, Harvard Medical School (A.G.R.) - both in Boston; the Division of Pediatric Infectious Diseases, Department of Pediatrics, Vanderbilt University Medical Center, Nashville (N.B.H.); the Department of Pediatrics, Baylor College of Medicine, Immunization Project, Texas Children's Hospital, Houston (J.A.B., L.C.S.), and the Department of Pediatrics, Division of Critical Care Medicine, University of Texas Southwestern, Children's Medical Center, Dallas (M.M.); the Division of Infectious Diseases, Children's Hospital Los Angeles and Departments of Pediatrics and Molecular Microbiology and Immunology, University of Southern California, Los Angeles (P.S.P.), the Division of Pediatric Hospital Medicine, UC San Diego-Rady Children's Hospital, San Diego (M.A.C.), the Division of Critical Care Medicine, UCSF Benioff Children's Hospital, Oakland (N.Z.C.), and the Department of Pediatrics, Divisions of Critical Care Medicine and Allergy, Immunology, and Bone Marrow Transplant, University of California, San Francisco, San Francisco (M.S.Z.) - all in California; Section of Pediatric Critical Care, Department of Pediatrics, Arkansas Children's Hospital, Little Rock (K.I.); the Division of Pediatric Critical Care Medicine, Nationwide Children's Hospital Columbus (K.E.B.), the Division of Critical Care Medicine, Department of Pediatrics, Akron Children's Hospital, Akron (R.A.N.), and the Department of Pediatrics, University of Cincinnati College of Medicine, Cincinnati Children's Hospital Medical Center, Cincinnati (M.A.S.) - all in Ohio; the Department of Pediatrics, Section of Critical Care Medicine, University of Colorado School of Medicine and Children's Hospital Colorado, Aurora (A.B.M.); the Department of Pediatrics, University of North Carolina at Chapel Hill Children's Hospital, Chapel Hill (T.C.W., S.P.S.); the Division of Pediatric Critical Care Medicine (E.H.M.) and the Department of Pediatrics (L.S.), Medical University of South Carolina, Charleston; the Division of Pediatric Infectious Diseases, Department of Pediatrics, Children's Mercy Kansas City, Kansas City, MO (J.E.S.); the Departments of Pediatrics and Microbiology, Division of Infectious Diseases, University of Mississippi Medical Center, Jackson (C.V.H.); the Department of Pediatrics, Division of Cardiology, Louisiana State University Health Sciences Center and Children's Hospital of New Orleans, New Orleans (T.T.B.); the Divisions of Pediatric Infectious Diseases and Pediatric Critical Care Medicine, Department of Pediatric and Adolescent Medicine, Mayo Clinic, Rochester (E.R.L.), and the Division of Pediatric Critical Care, University of Minnesota Masonic Children's Hospital, Minneapolis (J.R.H.) - both in Minnesota; the Division of Critical Care Medicine, Department of Anesthesiology and Critical Care, Children's Hospital of Philadelphia, Philadelphia (K.C.); the Ryan White Center for Pediatric Infectious Disease and Global Health, Department of Pediatrics, Indiana University School of Medicine, Indianapolis (S.S.B.); the Division of Pediatric Critical Care Medicine, Children's Hospital of Michigan, Central Michigan University, Detroit (S.M.H.), and the Division of Pediatric Critical Care Medicine, Department of Pediatrics, Mott Children's Hospital and University of Michigan, Ann Arbor (H.R.F.); the Division of Pediatric Critical Care, Department of Pediatrics, Children's Hospital and Medical Center, Omaha, NE (M.L.C.); the Division of Pediatric Critical Care, Department of Pediatrics, Cooperman Barnabas Medical Center, Livingston, NJ (S.J.G.); the Division of Critical Care Medicine, Department of Pediatrics, Northwestern University Feinberg School of Medicine, Ann and Robert H. Lurie Children's Hospital of Chicago, Chicago (B.M. Coates); the Division of Pediatric Critical Care Medicine, Department of Pediatrics, University of Alabama at Birmingham, Birmingham (M.K.); the Division of Pediatric Infectious Diseases, Department of Pediatrics, UHealth Holtz Children's Hospital, Miami (B.M. Chatani); and the Department of Pediatrics and Banner Children's at Diamond Children's Medical Center, University of Arizona, Tucson (K.V.T.).; Chiotos K; From the Covid-19 Response Team, Centers for Disease Control and Prevention (A.M.P., S.M.O., M.W.T., L.D.Z., A.P.C., M.M.P.), the Center for Childhood Infections and Vaccines of Children's Healthcare of Atlanta and the Department of Pediatrics, Emory University School of Medicine (S.K.), and the Division of Critical Care Medicine, Department of Pediatrics, Emory University School of Medicine, Children's Healthcare of Atlanta (K.M.T.) - all in Atlanta; the Department of Anesthesiology, Critical Care, and Pain Medicine, Boston Children's Hospital (M.M.N., A.G.R.), and the Departments of Anaesthesia and Pediatrics, Harvard Medical School (A.G.R.) - both in Boston; the Division of Pediatric Infectious Diseases, Department of Pediatrics, Vanderbilt University Medical Center, Nashville (N.B.H.); the Department of Pediatrics, Baylor College of Medicine, Immunization Project, Texas Children's Hospital, Houston (J.A.B., L.C.S.), and the Department of Pediatrics, Division of Critical Care Medicine, University of Texas Southwestern, Children's Medical Center, Dallas (M.M.); the Division of Infectious Diseases, Children's Hospital Los Angeles and Departments of Pediatrics and Molecular Microbiology and Immunology, University of Southern California, Los Angeles (P.S.P.), the Division of Pediatric Hospital Medicine, UC San Diego-Rady Children's Hospital, San Diego (M.A.C.), the Division of Critical Care Medicine, UCSF Benioff Children's Hospital, Oakland (N.Z.C.), and the Department of Pediatrics, Divisions of Critical Care Medicine and Allergy, Immunology, and Bone Marrow Transplant, University of California, San Francisco, San Francisco (M.S.Z.) - all in California; Section of Pediatric Critical Care, Department of Pediatrics, Arkansas Children's Hospital, Little Rock (K.I.); the Division of Pediatric Critical Care Medicine, Nationwide Children's Hospital Columbus (K.E.B.), the Division of Critical Care Medicine, Department of Pediatrics, Akron Children's Hospital, Akron (R.A.N.), and the Department of Pediatrics, University of Cincinnati College of Medicine, Cincinnati Children's Hospital Medical Center, Cincinnati (M.A.S.) - all in Ohio; the Department of Pediatrics, Section of Critical Care Medicine, University of Colorado School of Medicine and Children's Hospital Colorado, Aurora (A.B.M.); the Department of Pediatrics, University of North Carolina at Chapel Hill Children's Hospital, Chapel Hill (T.C.W., S.P.S.); the Division of Pediatric Critical Care Medicine (E.H.M.) and the Department of Pediatrics (L.S.), Medical University of South Carolina, Charleston; the Division of Pediatric Infectious Diseases, Department of Pediatrics, Children's Mercy Kansas City, Kansas City, MO (J.E.S.); the Departments of Pediatrics and Microbiology, Division of Infectious Diseases, University of Mississippi Medical Center, Jackson (C.V.H.); the Department of Pediatrics, Division of Cardiology, Louisiana State University Health Sciences Center and Children's Hospital of New Orleans, New Orleans (T.T.B.); the Divisions of Pediatric Infectious Diseases and Pediatric Critical Care Medicine, Department of Pediatric and Adolescent Medicine, Mayo Clinic, Rochester (E.R.L.), and the Division of Pediatric Critical Care, University of Minnesota Masonic Children's Hospital, Minneapolis (J.R.H.) - both in Minnesota; the Division of Critical Care Medicine, Department of Anesthesiology and Critical Care, Children's Hospital of Philadelphia, Philadelphia (K.C.); the Ryan White Center for Pediatric Infectious Disease and Global Health, Department of Pediatrics, Indiana University School of Medicine, Indianapolis (S.S.B.); the Division of Pediatric Critical Care Medicine, Children's Hospital of Michigan, Central Michigan University, Detroit (S.M.H.), and the Division of Pediatric Critical Care Medicine, Department of Pediatrics, Mott Children's Hospital and University of Michigan, Ann Arbor (H.R.F.); the Division of Pediatric Critical Care, Department of Pediatrics, Children's Hospital and Medical Center, Omaha, NE (M.L.C.); the Division of Pediatric Critical Care, Department of Pediatrics, Cooperman Barnabas Medical Center, Livingston, NJ (S.J.G.); the Division of Critical Care Medicine, Department of Pediatrics, Northwestern University Feinberg School of Medicine, Ann and Robert H. Lurie Children's Hospital of Chicago, Chicago (B.M. Coates); the Division of Pediatric Critical Care Medicine, Department of Pediatrics, University of Alabama at Birmingham, Birmingham (M.K.); the Division of Pediatric Infectious Diseases, Department of Pediatrics, UHealth Holtz Children's Hospital, Miami (B.M. Chatani); and the Department of Pediatrics and Banner Children's at Diamond Children's Medical Center, University of Arizona, Tucson (K.V.T.).; Bhumbra SS; From the Covid-19 Response Team, Centers for Disease Control and Prevention (A.M.P., S.M.O., M.W.T., L.D.Z., A.P.C., M.M.P.), the Center for Childhood Infections and Vaccines of Children's Healthcare of Atlanta and the Department of Pediatrics, Emory University School of Medicine (S.K.), and the Division of Critical Care Medicine, Department of Pediatrics, Emory University School of Medicine, Children's Healthcare of Atlanta (K.M.T.) - all in Atlanta; the Department of Anesthesiology, Critical Care, and Pain Medicine, Boston Children's Hospital (M.M.N., A.G.R.), and the Departments of Anaesthesia and Pediatrics, Harvard Medical School (A.G.R.) - both in Boston; the Division of Pediatric Infectious Diseases, Department of Pediatrics, Vanderbilt University Medical Center, Nashville (N.B.H.); the Department of Pediatrics, Baylor College of Medicine, Immunization Project, Texas Children's Hospital, Houston (J.A.B., L.C.S.), and the Department of Pediatrics, Division of Critical Care Medicine, University of Texas Southwestern, Children's Medical Center, Dallas (M.M.); the Division of Infectious Diseases, Children's Hospital Los Angeles and Departments of Pediatrics and Molecular Microbiology and Immunology, University of Southern California, Los Angeles (P.S.P.), the Division of Pediatric Hospital Medicine, UC San Diego-Rady Children's Hospital, San Diego (M.A.C.), the Division of Critical Care Medicine, UCSF Benioff Children's Hospital, Oakland (N.Z.C.), and the Department of Pediatrics, Divisions of Critical Care Medicine and Allergy, Immunology, and Bone Marrow Transplant, University of California, San Francisco, San Francisco (M.S.Z.) - all in California; Section of Pediatric Critical Care, Department of Pediatrics, Arkansas Children's Hospital, Little Rock (K.I.); the Division of Pediatric Critical Care Medicine, Nationwide Children's Hospital Columbus (K.E.B.), the Division of Critical Care Medicine, Department of Pediatrics, Akron Children's Hospital, Akron (R.A.N.), and the Department of Pediatrics, University of Cincinnati College of Medicine, Cincinnati Children's Hospital Medical Center, Cincinnati (M.A.S.) - all in Ohio; the Department of Pediatrics, Section of Critical Care Medicine, University of Colorado School of Medicine and Children's Hospital Colorado, Aurora (A.B.M.); the Department of Pediatrics, University of North Carolina at Chapel Hill Children's Hospital, Chapel Hill (T.C.W., S.P.S.); the Division of Pediatric Critical Care Medicine (E.H.M.) and the Department of Pediatrics (L.S.), Medical University of South Carolina, Charleston; the Division of Pediatric Infectious Diseases, Department of Pediatrics, Children's Mercy Kansas City, Kansas City, MO (J.E.S.); the Departments of Pediatrics and Microbiology, Division of Infectious Diseases, University of Mississippi Medical Center, Jackson (C.V.H.); the Department of Pediatrics, Division of Cardiology, Louisiana State University Health Sciences Center and Children's Hospital of New Orleans, New Orleans (T.T.B.); the Divisions of Pediatric Infectious Diseases and Pediatric Critical Care Medicine, Department of Pediatric and Adolescent Medicine, Mayo Clinic, Rochester (E.R.L.), and the Division of Pediatric Critical Care, University of Minnesota Masonic Children's Hospital, Minneapolis (J.R.H.) - both in Minnesota; the Division of Critical Care Medicine, Department of Anesthesiology and Critical Care, Children's Hospital of Philadelphia, Philadelphia (K.C.); the Ryan White Center for Pediatric Infectious Disease and Global Health, Department of Pediatrics, Indiana University School of Medicine, Indianapolis (S.S.B.); the Division of Pediatric Critical Care Medicine, Children's Hospital of Michigan, Central Michigan University, Detroit (S.M.H.), and the Division of Pediatric Critical Care Medicine, Department of Pediatrics, Mott Children's Hospital and University of Michigan, Ann Arbor (H.R.F.); the Division of Pediatric Critical Care, Department of Pediatrics, Children's Hospital and Medical Center, Omaha, NE (M.L.C.); the Division of Pediatric Critical Care, Department of Pediatrics, Cooperman Barnabas Medical Center, Livingston, NJ (S.J.G.); the Division of Critical Care Medicine, Department of Pediatrics, Northwestern University Feinberg School of Medicine, Ann and Robert H. Lurie Children's Hospital of Chicago, Chicago (B.M. Coates); the Division of Pediatric Critical Care Medicine, Department of Pediatrics, University of Alabama at Birmingham, Birmingham (M.K.); the Division of Pediatric Infectious Diseases, Department of Pediatrics, UHealth Holtz Children's Hospital, Miami (B.M. Chatani); and the Department of Pediatrics and Banner Children's at Diamond Children's Medical Center, University of Arizona, Tucson (K.V.T.).; Cvijanovich NZ; From the Covid-19 Response Team, Centers for Disease Control and Prevention (A.M.P., S.M.O., M.W.T., L.D.Z., A.P.C., M.M.P.), the Center for Childhood Infections and Vaccines of Children's Healthcare of Atlanta and the Department of Pediatrics, Emory University School of Medicine (S.K.), and the Division of Critical Care Medicine, Department of Pediatrics, Emory University School of Medicine, Children's Healthcare of Atlanta (K.M.T.) - all in Atlanta; the Department of Anesthesiology, Critical Care, and Pain Medicine, Boston Children's Hospital (M.M.N., A.G.R.), and the Departments of Anaesthesia and Pediatrics, Harvard Medical School (A.G.R.) - both in Boston; the Division of Pediatric Infectious Diseases, Department of Pediatrics, Vanderbilt University Medical Center, Nashville (N.B.H.); the Department of Pediatrics, Baylor College of Medicine, Immunization Project, Texas Children's Hospital, Houston (J.A.B., L.C.S.), and the Department of Pediatrics, Division of Critical Care Medicine, University of Texas Southwestern, Children's Medical Center, Dallas (M.M.); the Division of Infectious Diseases, Children's Hospital Los Angeles and Departments of Pediatrics and Molecular Microbiology and Immunology, University of Southern California, Los Angeles (P.S.P.), the Division of Pediatric Hospital Medicine, UC San Diego-Rady Children's Hospital, San Diego (M.A.C.), the Division of Critical Care Medicine, UCSF Benioff Children's Hospital, Oakland (N.Z.C.), and the Department of Pediatrics, Divisions of Critical Care Medicine and Allergy, Immunology, and Bone Marrow Transplant, University of California, San Francisco, San Francisco (M.S.Z.) - all in California; Section of Pediatric Critical Care, Department of Pediatrics, Arkansas Children's Hospital, Little Rock (K.I.); the Division of Pediatric Critical Care Medicine, Nationwide Children's Hospital Columbus (K.E.B.), the Division of Critical Care Medicine, Department of Pediatrics, Akron Children's Hospital, Akron (R.A.N.), and the Department of Pediatrics, University of Cincinnati College of Medicine, Cincinnati Children's Hospital Medical Center, Cincinnati (M.A.S.) - all in Ohio; the Department of Pediatrics, Section of Critical Care Medicine, University of Colorado School of Medicine and Children's Hospital Colorado, Aurora (A.B.M.); the Department of Pediatrics, University of North Carolina at Chapel Hill Children's Hospital, Chapel Hill (T.C.W., S.P.S.); the Division of Pediatric Critical Care Medicine (E.H.M.) and the Department of Pediatrics (L.S.), Medical University of South Carolina, Charleston; the Division of Pediatric Infectious Diseases, Department of Pediatrics, Children's Mercy Kansas City, Kansas City, MO (J.E.S.); the Departments of Pediatrics and Microbiology, Division of Infectious Diseases, University of Mississippi Medical Center, Jackson (C.V.H.); the Department of Pediatrics, Division of Cardiology, Louisiana State University Health Sciences Center and Children's Hospital of New Orleans, New Orleans (T.T.B.); the Divisions of Pediatric Infectious Diseases and Pediatric Critical Care Medicine, Department of Pediatric and Adolescent Medicine, Mayo Clinic, Rochester (E.R.L.), and the Division of Pediatric Critical Care, University of Minnesota Masonic Children's Hospital, Minneapolis (J.R.H.) - both in Minnesota; the Division of Critical Care Medicine, Department of Anesthesiology and Critical Care, Children's Hospital of Philadelphia, Philadelphia (K.C.); the Ryan White Center for Pediatric Infectious Disease and Global Health, Department of Pediatrics, Indiana University School of Medicine, Indianapolis (S.S.B.); the Division of Pediatric Critical Care Medicine, Children's Hospital of Michigan, Central Michigan University, Detroit (S.M.H.), and the Division of Pediatric Critical Care Medicine, Department of Pediatrics, Mott Children's Hospital and University of Michigan, Ann Arbor (H.R.F.); the Division of Pediatric Critical Care, Department of Pediatrics, Children's Hospital and Medical Center, Omaha, NE (M.L.C.); the Division of Pediatric Critical Care, Department of Pediatrics, Cooperman Barnabas Medical Center, Livingston, NJ (S.J.G.); the Division of Critical Care Medicine, Department of Pediatrics, Northwestern University Feinberg School of Medicine, Ann and Robert H. Lurie Children's Hospital of Chicago, Chicago (B.M. Coates); the Division of Pediatric Critical Care Medicine, Department of Pediatrics, University of Alabama at Birmingham, Birmingham (M.K.); the Division of Pediatric Infectious Diseases, Department of Pediatrics, UHealth Holtz Children's Hospital, Miami (B.M. Chatani); and the Department of Pediatrics and Banner Children's at Diamond Children's Medical Center, University of Arizona, Tucson (K.V.T.).; Heidemann SM; From the Covid-19 Response Team, Centers for Disease Control and Prevention (A.M.P., S.M.O., M.W.T., L.D.Z., A.P.C., M.M.P.), the Center for Childhood Infections and Vaccines of Children's Healthcare of Atlanta and the Department of Pediatrics, Emory University School of Medicine (S.K.), and the Division of Critical Care Medicine, Department of Pediatrics, Emory University School of Medicine, Children's Healthcare of Atlanta (K.M.T.) - all in Atlanta; the Department of Anesthesiology, Critical Care, and Pain Medicine, Boston Children's Hospital (M.M.N., A.G.R.), and the Departments of Anaesthesia and Pediatrics, Harvard Medical School (A.G.R.) - both in Boston; the Division of Pediatric Infectious Diseases, Department of Pediatrics, Vanderbilt University Medical Center, Nashville (N.B.H.); the Department of Pediatrics, Baylor College of Medicine, Immunization Project, Texas Children's Hospital, Houston (J.A.B., L.C.S.), and the Department of Pediatrics, Division of Critical Care Medicine, University of Texas Southwestern, Children's Medical Center, Dallas (M.M.); the Division of Infectious Diseases, Children's Hospital Los Angeles and Departments of Pediatrics and Molecular Microbiology and Immunology, University of Southern California, Los Angeles (P.S.P.), the Division of Pediatric Hospital Medicine, UC San Diego-Rady Children's Hospital, San Diego (M.A.C.), the Division of Critical Care Medicine, UCSF Benioff Children's Hospital, Oakland (N.Z.C.), and the Department of Pediatrics, Divisions of Critical Care Medicine and Allergy, Immunology, and Bone Marrow Transplant, University of California, San Francisco, San Francisco (M.S.Z.) - all in California; Section of Pediatric Critical Care, Department of Pediatrics, Arkansas Children's Hospital, Little Rock (K.I.); the Division of Pediatric Critical Care Medicine, Nationwide Children's Hospital Columbus (K.E.B.), the Division of Critical Care Medicine, Department of Pediatrics, Akron Children's Hospital, Akron (R.A.N.), and the Department of Pediatrics, University of Cincinnati College of Medicine, Cincinnati Children's Hospital Medical Center, Cincinnati (M.A.S.) - all in Ohio; the Department of Pediatrics, Section of Critical Care Medicine, University of Colorado School of Medicine and Children's Hospital Colorado, Aurora (A.B.M.); the Department of Pediatrics, University of North Carolina at Chapel Hill Children's Hospital, Chapel Hill (T.C.W., S.P.S.); the Division of Pediatric Critical Care Medicine (E.H.M.) and the Department of Pediatrics (L.S.), Medical University of South Carolina, Charleston; the Division of Pediatric Infectious Diseases, Department of Pediatrics, Children's Mercy Kansas City, Kansas City, MO (J.E.S.); the Departments of Pediatrics and Microbiology, Division of Infectious Diseases, University of Mississippi Medical Center, Jackson (C.V.H.); the Department of Pediatrics, Division of Cardiology, Louisiana State University Health Sciences Center and Children's Hospital of New Orleans, New Orleans (T.T.B.); the Divisions of Pediatric Infectious Diseases and Pediatric Critical Care Medicine, Department of Pediatric and Adolescent Medicine, Mayo Clinic, Rochester (E.R.L.), and the Division of Pediatric Critical Care, University of Minnesota Masonic Children's Hospital, Minneapolis (J.R.H.) - both in Minnesota; the Division of Critical Care Medicine, Department of Anesthesiology and Critical Care, Children's Hospital of Philadelphia, Philadelphia (K.C.); the Ryan White Center for Pediatric Infectious Disease and Global Health, Department of Pediatrics, Indiana University School of Medicine, Indianapolis (S.S.B.); the Division of Pediatric Critical Care Medicine, Children's Hospital of Michigan, Central Michigan University, Detroit (S.M.H.), and the Division of Pediatric Critical Care Medicine, Department of Pediatrics, Mott Children's Hospital and University of Michigan, Ann Arbor (H.R.F.); the Division of Pediatric Critical Care, Department of Pediatrics, Children's Hospital and Medical Center, Omaha, NE (M.L.C.); the Division of Pediatric Critical Care, Department of Pediatrics, Cooperman Barnabas Medical Center, Livingston, NJ (S.J.G.); the Division of Critical Care Medicine, Department of Pediatrics, Northwestern University Feinberg School of Medicine, Ann and Robert H. Lurie Children's Hospital of Chicago, Chicago (B.M. Coates); the Division of Pediatric Critical Care Medicine, Department of Pediatrics, University of Alabama at Birmingham, Birmingham (M.K.); the Division of Pediatric Infectious Diseases, Department of Pediatrics, UHealth Holtz Children's Hospital, Miami (B.M. Chatani); and the Department of Pediatrics and Banner Children's at Diamond Children's Medical Center, University of Arizona, Tucson (K.V.T.).; Cullimore ML; From the Covid-19 Response Team, Centers for Disease Control and Prevention (A.M.P., S.M.O., M.W.T., L.D.Z., A.P.C., M.M.P.), the Center for Childhood Infections and Vaccines of Children's Healthcare of Atlanta and the Department of Pediatrics, Emory University School of Medicine (S.K.), and the Division of Critical Care Medicine, Department of Pediatrics, Emory University School of Medicine, Children's Healthcare of Atlanta (K.M.T.) - all in Atlanta; the Department of Anesthesiology, Critical Care, and Pain Medicine, Boston Children's Hospital (M.M.N., A.G.R.), and the Departments of Anaesthesia and Pediatrics, Harvard Medical School (A.G.R.) - both in Boston; the Division of Pediatric Infectious Diseases, Department of Pediatrics, Vanderbilt University Medical Center, Nashville (N.B.H.); the Department of Pediatrics, Baylor College of Medicine, Immunization Project, Texas Children's Hospital, Houston (J.A.B., L.C.S.), and the Department of Pediatrics, Division of Critical Care Medicine, University of Texas Southwestern, Children's Medical Center, Dallas (M.M.); the Division of Infectious Diseases, Children's Hospital Los Angeles and Departments of Pediatrics and Molecular Microbiology and Immunology, University of Southern California, Los Angeles (P.S.P.), the Division of Pediatric Hospital Medicine, UC San Diego-Rady Children's Hospital, San Diego (M.A.C.), the Division of Critical Care Medicine, UCSF Benioff Children's Hospital, Oakland (N.Z.C.), and the Department of Pediatrics, Divisions of Critical Care Medicine and Allergy, Immunology, and Bone Marrow Transplant, University of California, San Francisco, San Francisco (M.S.Z.) - all in California; Section of Pediatric Critical Care, Department of Pediatrics, Arkansas Children's Hospital, Little Rock (K.I.); the Division of Pediatric Critical Care Medicine, Nationwide Children's Hospital Columbus (K.E.B.), the Division of Critical Care Medicine, Department of Pediatrics, Akron Children's Hospital, Akron (R.A.N.), and the Department of Pediatrics, University of Cincinnati College of Medicine, Cincinnati Children's Hospital Medical Center, Cincinnati (M.A.S.) - all in Ohio; the Department of Pediatrics, Section of Critical Care Medicine, University of Colorado School of Medicine and Children's Hospital Colorado, Aurora (A.B.M.); the Department of Pediatrics, University of North Carolina at Chapel Hill Children's Hospital, Chapel Hill (T.C.W., S.P.S.); the Division of Pediatric Critical Care Medicine (E.H.M.) and the Department of Pediatrics (L.S.), Medical University of South Carolina, Charleston; the Division of Pediatric Infectious Diseases, Department of Pediatrics, Children's Mercy Kansas City, Kansas City, MO (J.E.S.); the Departments of Pediatrics and Microbiology, Division of Infectious Diseases, University of Mississippi Medical Center, Jackson (C.V.H.); the Department of Pediatrics, Division of Cardiology, Louisiana State University Health Sciences Center and Children's Hospital of New Orleans, New Orleans (T.T.B.); the Divisions of Pediatric Infectious Diseases and Pediatric Critical Care Medicine, Department of Pediatric and Adolescent Medicine, Mayo Clinic, Rochester (E.R.L.), and the Division of Pediatric Critical Care, University of Minnesota Masonic Children's Hospital, Minneapolis (J.R.H.) - both in Minnesota; the Division of Critical Care Medicine, Department of Anesthesiology and Critical Care, Children's Hospital of Philadelphia, Philadelphia (K.C.); the Ryan White Center for Pediatric Infectious Disease and Global Health, Department of Pediatrics, Indiana University School of Medicine, Indianapolis (S.S.B.); the Division of Pediatric Critical Care Medicine, Children's Hospital of Michigan, Central Michigan University, Detroit (S.M.H.), and the Division of Pediatric Critical Care Medicine, Department of Pediatrics, Mott Children's Hospital and University of Michigan, Ann Arbor (H.R.F.); the Division of Pediatric Critical Care, Department of Pediatrics, Children's Hospital and Medical Center, Omaha, NE (M.L.C.); the Division of Pediatric Critical Care, Department of Pediatrics, Cooperman Barnabas Medical Center, Livingston, NJ (S.J.G.); the Division of Critical Care Medicine, Department of Pediatrics, Northwestern University Feinberg School of Medicine, Ann and Robert H. Lurie Children's Hospital of Chicago, Chicago (B.M. Coates); the Division of Pediatric Critical Care Medicine, Department of Pediatrics, University of Alabama at Birmingham, Birmingham (M.K.); the Division of Pediatric Infectious Diseases, Department of Pediatrics, UHealth Holtz Children's Hospital, Miami (B.M. Chatani); and the Department of Pediatrics and Banner Children's at Diamond Children's Medical Center, University of Arizona, Tucson (K.V.T.).; Gertz SJ; From the Covid-19 Response Team, Centers for Disease Control and Prevention (A.M.P., S.M.O., M.W.T., L.D.Z., A.P.C., M.M.P.), the Center for Childhood Infections and Vaccines of Children's Healthcare of Atlanta and the Department of Pediatrics, Emory University School of Medicine (S.K.), and the Division of Critical Care Medicine, Department of Pediatrics, Emory University School of Medicine, Children's Healthcare of Atlanta (K.M.T.) - all in Atlanta; the Department of Anesthesiology, Critical Care, and Pain Medicine, Boston Children's Hospital (M.M.N., A.G.R.), and the Departments of Anaesthesia and Pediatrics, Harvard Medical School (A.G.R.) - both in Boston; the Division of Pediatric Infectious Diseases, Department of Pediatrics, Vanderbilt University Medical Center, Nashville (N.B.H.); the Department of Pediatrics, Baylor College of Medicine, Immunization Project, Texas Children's Hospital, Houston (J.A.B., L.C.S.), and the Department of Pediatrics, Division of Critical Care Medicine, University of Texas Southwestern, Children's Medical Center, Dallas (M.M.); the Division of Infectious Diseases, Children's Hospital Los Angeles and Departments of Pediatrics and Molecular Microbiology and Immunology, University of Southern California, Los Angeles (P.S.P.), the Division of Pediatric Hospital Medicine, UC San Diego-Rady Children's Hospital, San Diego (M.A.C.), the Division of Critical Care Medicine, UCSF Benioff Children's Hospital, Oakland (N.Z.C.), and the Department of Pediatrics, Divisions of Critical Care Medicine and Allergy, Immunology, and Bone Marrow Transplant, University of California, San Francisco, San Francisco (M.S.Z.) - all in California; Section of Pediatric Critical Care, Department of Pediatrics, Arkansas Children's Hospital, Little Rock (K.I.); the Division of Pediatric Critical Care Medicine, Nationwide Children's Hospital Columbus (K.E.B.), the Division of Critical Care Medicine, Department of Pediatrics, Akron Children's Hospital, Akron (R.A.N.), and the Department of Pediatrics, University of Cincinnati College of Medicine, Cincinnati Children's Hospital Medical Center, Cincinnati (M.A.S.) - all in Ohio; the Department of Pediatrics, Section of Critical Care Medicine, University of Colorado School of Medicine and Children's Hospital Colorado, Aurora (A.B.M.); the Department of Pediatrics, University of North Carolina at Chapel Hill Children's Hospital, Chapel Hill (T.C.W., S.P.S.); the Division of Pediatric Critical Care Medicine (E.H.M.) and the Department of Pediatrics (L.S.), Medical University of South Carolina, Charleston; the Division of Pediatric Infectious Diseases, Department of Pediatrics, Children's Mercy Kansas City, Kansas City, MO (J.E.S.); the Departments of Pediatrics and Microbiology, Division of Infectious Diseases, University of Mississippi Medical Center, Jackson (C.V.H.); the Department of Pediatrics, Division of Cardiology, Louisiana State University Health Sciences Center and Children's Hospital of New Orleans, New Orleans (T.T.B.); the Divisions of Pediatric Infectious Diseases and Pediatric Critical Care Medicine, Department of Pediatric and Adolescent Medicine, Mayo Clinic, Rochester (E.R.L.), and the Division of Pediatric Critical Care, University of Minnesota Masonic Children's Hospital, Minneapolis (J.R.H.) - both in Minnesota; the Division of Critical Care Medicine, Department of Anesthesiology and Critical Care, Children's Hospital of Philadelphia, Philadelphia (K.C.); the Ryan White Center for Pediatric Infectious Disease and Global Health, Department of Pediatrics, Indiana University School of Medicine, Indianapolis (S.S.B.); the Division of Pediatric Critical Care Medicine, Children's Hospital of Michigan, Central Michigan University, Detroit (S.M.H.), and the Division of Pediatric Critical Care Medicine, Department of Pediatrics, Mott Children's Hospital and University of Michigan, Ann Arbor (H.R.F.); the Division of Pediatric Critical Care, Department of Pediatrics, Children's Hospital and Medical Center, Omaha, NE (M.L.C.); the Division of Pediatric Critical Care, Department of Pediatrics, Cooperman Barnabas Medical Center, Livingston, NJ (S.J.G.); the Division of Critical Care Medicine, Department of Pediatrics, Northwestern University Feinberg School of Medicine, Ann and Robert H. Lurie Children's Hospital of Chicago, Chicago (B.M. Coates); the Division of Pediatric Critical Care Medicine, Department of Pediatrics, University of Alabama at Birmingham, Birmingham (M.K.); the Division of Pediatric Infectious Diseases, Department of Pediatrics, UHealth Holtz Children's Hospital, Miami (B.M. Chatani); and the Department of Pediatrics and Banner Children's at Diamond Children's Medical Center, University of Arizona, Tucson (K.V.T.).; Coates BM; From the Covid-19 Response Team, Centers for Disease Control and Prevention (A.M.P., S.M.O., M.W.T., L.D.Z., A.P.C., M.M.P.), the Center for Childhood Infections and Vaccines of Children's Healthcare of Atlanta and the Department of Pediatrics, Emory University School of Medicine (S.K.), and the Division of Critical Care Medicine, Department of Pediatrics, Emory University School of Medicine, Children's Healthcare of Atlanta (K.M.T.) - all in Atlanta; the Department of Anesthesiology, Critical Care, and Pain Medicine, Boston Children's Hospital (M.M.N., A.G.R.), and the Departments of Anaesthesia and Pediatrics, Harvard Medical School (A.G.R.) - both in Boston; the Division of Pediatric Infectious Diseases, Department of Pediatrics, Vanderbilt University Medical Center, Nashville (N.B.H.); the Department of Pediatrics, Baylor College of Medicine, Immunization Project, Texas Children's Hospital, Houston (J.A.B., L.C.S.), and the Department of Pediatrics, Division of Critical Care Medicine, University of Texas Southwestern, Children's Medical Center, Dallas (M.M.); the Division of Infectious Diseases, Children's Hospital Los Angeles and Departments of Pediatrics and Molecular Microbiology and Immunology, University of Southern California, Los Angeles (P.S.P.), the Division of Pediatric Hospital Medicine, UC San Diego-Rady Children's Hospital, San Diego (M.A.C.), the Division of Critical Care Medicine, UCSF Benioff Children's Hospital, Oakland (N.Z.C.), and the Department of Pediatrics, Divisions of Critical Care Medicine and Allergy, Immunology, and Bone Marrow Transplant, University of California, San Francisco, San Francisco (M.S.Z.) - all in California; Section of Pediatric Critical Care, Department of Pediatrics, Arkansas Children's Hospital, Little Rock (K.I.); the Division of Pediatric Critical Care Medicine, Nationwide Children's Hospital Columbus (K.E.B.), the Division of Critical Care Medicine, Department of Pediatrics, Akron Children's Hospital, Akron (R.A.N.), and the Department of Pediatrics, University of Cincinnati College of Medicine, Cincinnati Children's Hospital Medical Center, Cincinnati (M.A.S.) - all in Ohio; the Department of Pediatrics, Section of Critical Care Medicine, University of Colorado School of Medicine and Children's Hospital Colorado, Aurora (A.B.M.); the Department of Pediatrics, University of North Carolina at Chapel Hill Children's Hospital, Chapel Hill (T.C.W., S.P.S.); the Division of Pediatric Critical Care Medicine (E.H.M.) and the Department of Pediatrics (L.S.), Medical University of South Carolina, Charleston; the Division of Pediatric Infectious Diseases, Department of Pediatrics, Children's Mercy Kansas City, Kansas City, MO (J.E.S.); the Departments of Pediatrics and Microbiology, Division of Infectious Diseases, University of Mississippi Medical Center, Jackson (C.V.H.); the Department of Pediatrics, Division of Cardiology, Louisiana State University Health Sciences Center and Children's Hospital of New Orleans, New Orleans (T.T.B.); the Divisions of Pediatric Infectious Diseases and Pediatric Critical Care Medicine, Department of Pediatric and Adolescent Medicine, Mayo Clinic, Rochester (E.R.L.), and the Division of Pediatric Critical Care, University of Minnesota Masonic Children's Hospital, Minneapolis (J.R.H.) - both in Minnesota; the Division of Critical Care Medicine, Department of Anesthesiology and Critical Care, Children's Hospital of Philadelphia, Philadelphia (K.C.); the Ryan White Center for Pediatric Infectious Disease and Global Health, Department of Pediatrics, Indiana University School of Medicine, Indianapolis (S.S.B.); the Division of Pediatric Critical Care Medicine, Children's Hospital of Michigan, Central Michigan University, Detroit (S.M.H.), and the Division of Pediatric Critical Care Medicine, Department of Pediatrics, Mott Children's Hospital and University of Michigan, Ann Arbor (H.R.F.); the Division of Pediatric Critical Care, Department of Pediatrics, Children's Hospital and Medical Center, Omaha, NE (M.L.C.); the Division of Pediatric Critical Care, Department of Pediatrics, Cooperman Barnabas Medical Center, Livingston, NJ (S.J.G.); the Division of Critical Care Medicine, Department of Pediatrics, Northwestern University Feinberg School of Medicine, Ann and Robert H. Lurie Children's Hospital of Chicago, Chicago (B.M. Coates); the Division of Pediatric Critical Care Medicine, Department of Pediatrics, University of Alabama at Birmingham, Birmingham (M.K.); the Division of Pediatric Infectious Diseases, Department of Pediatrics, UHealth Holtz Children's Hospital, Miami (B.M. Chatani); and the Department of Pediatrics and Banner Children's at Diamond Children's Medical Center, University of Arizona, Tucson (K.V.T.).; Staat MA; From the Covid-19 Response Team, Centers for Disease Control and Prevention (A.M.P., S.M.O., M.W.T., L.D.Z., A.P.C., M.M.P.), the Center for Childhood Infections and Vaccines of Children's Healthcare of Atlanta and the Department of Pediatrics, Emory University School of Medicine (S.K.), and the Division of Critical Care Medicine, Department of Pediatrics, Emory University School of Medicine, Children's Healthcare of Atlanta (K.M.T.) - all in Atlanta; the Department of Anesthesiology, Critical Care, and Pain Medicine, Boston Children's Hospital (M.M.N., A.G.R.), and the Departments of Anaesthesia and Pediatrics, Harvard Medical School (A.G.R.) - both in Boston; the Division of Pediatric Infectious Diseases, Department of Pediatrics, Vanderbilt University Medical Center, Nashville (N.B.H.); the Department of Pediatrics, Baylor College of Medicine, Immunization Project, Texas Children's Hospital, Houston (J.A.B., L.C.S.), and the Department of Pediatrics, Division of Critical Care Medicine, University of Texas Southwestern, Children's Medical Center, Dallas (M.M.); the Division of Infectious Diseases, Children's Hospital Los Angeles and Departments of Pediatrics and Molecular Microbiology and Immunology, University of Southern California, Los Angeles (P.S.P.), the Division of Pediatric Hospital Medicine, UC San Diego-Rady Children's Hospital, San Diego (M.A.C.), the Division of Critical Care Medicine, UCSF Benioff Children's Hospital, Oakland (N.Z.C.), and the Department of Pediatrics, Divisions of Critical Care Medicine and Allergy, Immunology, and Bone Marrow Transplant, University of California, San Francisco, San Francisco (M.S.Z.) - all in California; Section of Pediatric Critical Care, Department of Pediatrics, Arkansas Children's Hospital, Little Rock (K.I.); the Division of Pediatric Critical Care Medicine, Nationwide Children's Hospital Columbus (K.E.B.), the Division of Critical Care Medicine, Department of Pediatrics, Akron Children's Hospital, Akron (R.A.N.), and the Department of Pediatrics, University of Cincinnati College of Medicine, Cincinnati Children's Hospital Medical Center, Cincinnati (M.A.S.) - all in Ohio; the Department of Pediatrics, Section of Critical Care Medicine, University of Colorado School of Medicine and Children's Hospital Colorado, Aurora (A.B.M.); the Department of Pediatrics, University of North Carolina at Chapel Hill Children's Hospital, Chapel Hill (T.C.W., S.P.S.); the Division of Pediatric Critical Care Medicine (E.H.M.) and the Department of Pediatrics (L.S.), Medical University of South Carolina, Charleston; the Division of Pediatric Infectious Diseases, Department of Pediatrics, Children's Mercy Kansas City, Kansas City, MO (J.E.S.); the Departments of Pediatrics and Microbiology, Division of Infectious Diseases, University of Mississippi Medical Center, Jackson (C.V.H.); the Department of Pediatrics, Division of Cardiology, Louisiana State University Health Sciences Center and Children's Hospital of New Orleans, New Orleans (T.T.B.); the Divisions of Pediatric Infectious Diseases and Pediatric Critical Care Medicine, Department of Pediatric and Adolescent Medicine, Mayo Clinic, Rochester (E.R.L.), and the Division of Pediatric Critical Care, University of Minnesota Masonic Children's Hospital, Minneapolis (J.R.H.) - both in Minnesota; the Division of Critical Care Medicine, Department of Anesthesiology and Critical Care, Children's Hospital of Philadelphia, Philadelphia (K.C.); the Ryan White Center for Pediatric Infectious Disease and Global Health, Department of Pediatrics, Indiana University School of Medicine, Indianapolis (S.S.B.); the Division of Pediatric Critical Care Medicine, Children's Hospital of Michigan, Central Michigan University, Detroit (S.M.H.), and the Division of Pediatric Critical Care Medicine, Department of Pediatrics, Mott Children's Hospital and University of Michigan, Ann Arbor (H.R.F.); the Division of Pediatric Critical Care, Department of Pediatrics, Children's Hospital and Medical Center, Omaha, NE (M.L.C.); the Division of Pediatric Critical Care, Department of Pediatrics, Cooperman Barnabas Medical Center, Livingston, NJ (S.J.G.); the Division of Critical Care Medicine, Department of Pediatrics, Northwestern University Feinberg School of Medicine, Ann and Robert H. Lurie Children's Hospital of Chicago, Chicago (B.M. Coates); the Division of Pediatric Critical Care Medicine, Department of Pediatrics, University of Alabama at Birmingham, Birmingham (M.K.); the Division of Pediatric Infectious Diseases, Department of Pediatrics, UHealth Holtz Children's Hospital, Miami (B.M. Chatani); and the Department of Pediatrics and Banner Children's at Diamond Children's Medical Center, University of Arizona, Tucson (K.V.T.).; Zinter MS; From the Covid-19 Response Team, Centers for Disease Control and Prevention (A.M.P., S.M.O., M.W.T., L.D.Z., A.P.C., M.M.P.), the Center for Childhood Infections and Vaccines of Children's Healthcare of Atlanta and the Department of Pediatrics, Emory University School of Medicine (S.K.), and the Division of Critical Care Medicine, Department of Pediatrics, Emory University School of Medicine, Children's Healthcare of Atlanta (K.M.T.) - all in Atlanta; the Department of Anesthesiology, Critical Care, and Pain Medicine, Boston Children's Hospital (M.M.N., A.G.R.), and the Departments of Anaesthesia and Pediatrics, Harvard Medical School (A.G.R.) - both in Boston; the Division of Pediatric Infectious Diseases, Department of Pediatrics, Vanderbilt University Medical Center, Nashville (N.B.H.); the Department of Pediatrics, Baylor College of Medicine, Immunization Project, Texas Children's Hospital, Houston (J.A.B., L.C.S.), and the Department of Pediatrics, Division of Critical Care Medicine, University of Texas Southwestern, Children's Medical Center, Dallas (M.M.); the Division of Infectious Diseases, Children's Hospital Los Angeles and Departments of Pediatrics and Molecular Microbiology and Immunology, University of Southern California, Los Angeles (P.S.P.), the Division of Pediatric Hospital Medicine, UC San Diego-Rady Children's Hospital, San Diego (M.A.C.), the Division of Critical Care Medicine, UCSF Benioff Children's Hospital, Oakland (N.Z.C.), and the Department of Pediatrics, Divisions of Critical Care Medicine and Allergy, Immunology, and Bone Marrow Transplant, University of California, San Francisco, San Francisco (M.S.Z.) - all in California; Section of Pediatric Critical Care, Department of Pediatrics, Arkansas Children's Hospital, Little Rock (K.I.); the Division of Pediatric Critical Care Medicine, Nationwide Children's Hospital Columbus (K.E.B.), the Division of Critical Care Medicine, Department of Pediatrics, Akron Children's Hospital, Akron (R.A.N.), and the Department of Pediatrics, University of Cincinnati College of Medicine, Cincinnati Children's Hospital Medical Center, Cincinnati (M.A.S.) - all in Ohio; the Department of Pediatrics, Section of Critical Care Medicine, University of Colorado School of Medicine and Children's Hospital Colorado, Aurora (A.B.M.); the Department of Pediatrics, University of North Carolina at Chapel Hill Children's Hospital, Chapel Hill (T.C.W., S.P.S.); the Division of Pediatric Critical Care Medicine (E.H.M.) and the Department of Pediatrics (L.S.), Medical University of South Carolina, Charleston; the Division of Pediatric Infectious Diseases, Department of Pediatrics, Children's Mercy Kansas City, Kansas City, MO (J.E.S.); the Departments of Pediatrics and Microbiology, Division of Infectious Diseases, University of Mississippi Medical Center, Jackson (C.V.H.); the Department of Pediatrics, Division of Cardiology, Louisiana State University Health Sciences Center and Children's Hospital of New Orleans, New Orleans (T.T.B.); the Divisions of Pediatric Infectious Diseases and Pediatric Critical Care Medicine, Department of Pediatric and Adolescent Medicine, Mayo Clinic, Rochester (E.R.L.), and the Division of Pediatric Critical Care, University of Minnesota Masonic Children's Hospital, Minneapolis (J.R.H.) - both in Minnesota; the Division of Critical Care Medicine, Department of Anesthesiology and Critical Care, Children's Hospital of Philadelphia, Philadelphia (K.C.); the Ryan White Center for Pediatric Infectious Disease and Global Health, Department of Pediatrics, Indiana University School of Medicine, Indianapolis (S.S.B.); the Division of Pediatric Critical Care Medicine, Children's Hospital of Michigan, Central Michigan University, Detroit (S.M.H.), and the Division of Pediatric Critical Care Medicine, Department of Pediatrics, Mott Children's Hospital and University of Michigan, Ann Arbor (H.R.F.); the Division of Pediatric Critical Care, Department of Pediatrics, Children's Hospital and Medical Center, Omaha, NE (M.L.C.); the Division of Pediatric Critical Care, Department of Pediatrics, Cooperman Barnabas Medical Center, Livingston, NJ (S.J.G.); the Division of Critical Care Medicine, Department of Pediatrics, Northwestern University Feinberg School of Medicine, Ann and Robert H. Lurie Children's Hospital of Chicago, Chicago (B.M. Coates); the Division of Pediatric Critical Care Medicine, Department of Pediatrics, University of Alabama at Birmingham, Birmingham (M.K.); the Division of Pediatric Infectious Diseases, Department of Pediatrics, UHealth Holtz Children's Hospital, Miami (B.M. Chatani); and the Department of Pediatrics and Banner Children's at Diamond Children's Medical Center, University of Arizona, Tucson (K.V.T.).; Kong M; From the Covid-19 Response Team, Centers for Disease Control and Prevention (A.M.P., S.M.O., M.W.T., L.D.Z., A.P.C., M.M.P.), the Center for Childhood Infections and Vaccines of Children's Healthcare of Atlanta and the Department of Pediatrics, Emory University School of Medicine (S.K.), and the Division of Critical Care Medicine, Department of Pediatrics, Emory University School of Medicine, Children's Healthcare of Atlanta (K.M.T.) - all in Atlanta; the Department of Anesthesiology, Critical Care, and Pain Medicine, Boston Children's Hospital (M.M.N., A.G.R.), and the Departments of Anaesthesia and Pediatrics, Harvard Medical School (A.G.R.) - both in Boston; the Division of Pediatric Infectious Diseases, Department of Pediatrics, Vanderbilt University Medical Center, Nashville (N.B.H.); the Department of Pediatrics, Baylor College of Medicine, Immunization Project, Texas Children's Hospital, Houston (J.A.B., L.C.S.), and the Department of Pediatrics, Division of Critical Care Medicine, University of Texas Southwestern, Children's Medical Center, Dallas (M.M.); the Division of Infectious Diseases, Children's Hospital Los Angeles and Departments of Pediatrics and Molecular Microbiology and Immunology, University of Southern California, Los Angeles (P.S.P.), the Division of Pediatric Hospital Medicine, UC San Diego-Rady Children's Hospital, San Diego (M.A.C.), the Division of Critical Care Medicine, UCSF Benioff Children's Hospital, Oakland (N.Z.C.), and the Department of Pediatrics, Divisions of Critical Care Medicine and Allergy, Immunology, and Bone Marrow Transplant, University of California, San Francisco, San Francisco (M.S.Z.) - all in California; Section of Pediatric Critical Care, Department of Pediatrics, Arkansas Children's Hospital, Little Rock (K.I.); the Division of Pediatric Critical Care Medicine, Nationwide Children's Hospital Columbus (K.E.B.), the Division of Critical Care Medicine, Department of Pediatrics, Akron Children's Hospital, Akron (R.A.N.), and the Department of Pediatrics, University of Cincinnati College of Medicine, Cincinnati Children's Hospital Medical Center, Cincinnati (M.A.S.) - all in Ohio; the Department of Pediatrics, Section of Critical Care Medicine, University of Colorado School of Medicine and Children's Hospital Colorado, Aurora (A.B.M.); the Department of Pediatrics, University of North Carolina at Chapel Hill Children's Hospital, Chapel Hill (T.C.W., S.P.S.); the Division of Pediatric Critical Care Medicine (E.H.M.) and the Department of Pediatrics (L.S.), Medical University of South Carolina, Charleston; the Division of Pediatric Infectious Diseases, Department of Pediatrics, Children's Mercy Kansas City, Kansas City, MO (J.E.S.); the Departments of Pediatrics and Microbiology, Division of Infectious Diseases, University of Mississippi Medical Center, Jackson (C.V.H.); the Department of Pediatrics, Division of Cardiology, Louisiana State University Health Sciences Center and Children's Hospital of New Orleans, New Orleans (T.T.B.); the Divisions of Pediatric Infectious Diseases and Pediatric Critical Care Medicine, Department of Pediatric and Adolescent Medicine, Mayo Clinic, Rochester (E.R.L.), and the Division of Pediatric Critical Care, University of Minnesota Masonic Children's Hospital, Minneapolis (J.R.H.) - both in Minnesota; the Division of Critical Care Medicine, Department of Anesthesiology and Critical Care, Children's Hospital of Philadelphia, Philadelphia (K.C.); the Ryan White Center for Pediatric Infectious Disease and Global Health, Department of Pediatrics, Indiana University School of Medicine, Indianapolis (S.S.B.); the Division of Pediatric Critical Care Medicine, Children's Hospital of Michigan, Central Michigan University, Detroit (S.M.H.), and the Division of Pediatric Critical Care Medicine, Department of Pediatrics, Mott Children's Hospital and University of Michigan, Ann Arbor (H.R.F.); the Division of Pediatric Critical Care, Department of Pediatrics, Children's Hospital and Medical Center, Omaha, NE (M.L.C.); the Division of Pediatric Critical Care, Department of Pediatrics, Cooperman Barnabas Medical Center, Livingston, NJ (S.J.G.); the Division of Critical Care Medicine, Department of Pediatrics, Northwestern University Feinberg School of Medicine, Ann and Robert H. Lurie Children's Hospital of Chicago, Chicago (B.M. Coates); the Division of Pediatric Critical Care Medicine, Department of Pediatrics, University of Alabama at Birmingham, Birmingham (M.K.); the Division of Pediatric Infectious Diseases, Department of Pediatrics, UHealth Holtz Children's Hospital, Miami (B.M. Chatani); and the Department of Pediatrics and Banner Children's at Diamond Children's Medical Center, University of Arizona, Tucson (K.V.T.).; Chatani BM; From the Covid-19 Response Team, Centers for Disease Control and Prevention (A.M.P., S.M.O., M.W.T., L.D.Z., A.P.C., M.M.P.), the Center for Childhood Infections and Vaccines of Children's Healthcare of Atlanta and the Department of Pediatrics, Emory University School of Medicine (S.K.), and the Division of Critical Care Medicine, Department of Pediatrics, Emory University School of Medicine, Children's Healthcare of Atlanta (K.M.T.) - all in Atlanta; the Department of Anesthesiology, Critical Care, and Pain Medicine, Boston Children's Hospital (M.M.N., A.G.R.), and the Departments of Anaesthesia and Pediatrics, Harvard Medical School (A.G.R.) - both in Boston; the Division of Pediatric Infectious Diseases, Department of Pediatrics, Vanderbilt University Medical Center, Nashville (N.B.H.); the Department of Pediatrics, Baylor College of Medicine, Immunization Project, Texas Children's Hospital, Houston (J.A.B., L.C.S.), and the Department of Pediatrics, Division of Critical Care Medicine, University of Texas Southwestern, Children's Medical Center, Dallas (M.M.); the Division of Infectious Diseases, Children's Hospital Los Angeles and Departments of Pediatrics and Molecular Microbiology and Immunology, University of Southern California, Los Angeles (P.S.P.), the Division of Pediatric Hospital Medicine, UC San Diego-Rady Children's Hospital, San Diego (M.A.C.), the Division of Critical Care Medicine, UCSF Benioff Children's Hospital, Oakland (N.Z.C.), and the Department of Pediatrics, Divisions of Critical Care Medicine and Allergy, Immunology, and Bone Marrow Transplant, University of California, San Francisco, San Francisco (M.S.Z.) - all in California; Section of Pediatric Critical Care, Department of Pediatrics, Arkansas Children's Hospital, Little Rock (K.I.); the Division of Pediatric Critical Care Medicine, Nationwide Children's Hospital Columbus (K.E.B.), the Division of Critical Care Medicine, Department of Pediatrics, Akron Children's Hospital, Akron (R.A.N.), and the Department of Pediatrics, University of Cincinnati College of Medicine, Cincinnati Children's Hospital Medical Center, Cincinnati (M.A.S.) - all in Ohio; the Department of Pediatrics, Section of Critical Care Medicine, University of Colorado School of Medicine and Children's Hospital Colorado, Aurora (A.B.M.); the Department of Pediatrics, University of North Carolina at Chapel Hill Children's Hospital, Chapel Hill (T.C.W., S.P.S.); the Division of Pediatric Critical Care Medicine (E.H.M.) and the Department of Pediatrics (L.S.), Medical University of South Carolina, Charleston; the Division of Pediatric Infectious Diseases, Department of Pediatrics, Children's Mercy Kansas City, Kansas City, MO (J.E.S.); the Departments of Pediatrics and Microbiology, Division of Infectious Diseases, University of Mississippi Medical Center, Jackson (C.V.H.); the Department of Pediatrics, Division of Cardiology, Louisiana State University Health Sciences Center and Children's Hospital of New Orleans, New Orleans (T.T.B.); the Divisions of Pediatric Infectious Diseases and Pediatric Critical Care Medicine, Department of Pediatric and Adolescent Medicine, Mayo Clinic, Rochester (E.R.L.), and the Division of Pediatric Critical Care, University of Minnesota Masonic Children's Hospital, Minneapolis (J.R.H.) - both in Minnesota; the Division of Critical Care Medicine, Department of Anesthesiology and Critical Care, Children's Hospital of Philadelphia, Philadelphia (K.C.); the Ryan White Center for Pediatric Infectious Disease and Global Health, Department of Pediatrics, Indiana University School of Medicine, Indianapolis (S.S.B.); the Division of Pediatric Critical Care Medicine, Children's Hospital of Michigan, Central Michigan University, Detroit (S.M.H.), and the Division of Pediatric Critical Care Medicine, Department of Pediatrics, Mott Children's Hospital and University of Michigan, Ann Arbor (H.R.F.); the Division of Pediatric Critical Care, Department of Pediatrics, Children's Hospital and Medical Center, Omaha, NE (M.L.C.); the Division of Pediatric Critical Care, Department of Pediatrics, Cooperman Barnabas Medical Center, Livingston, NJ (S.J.G.); the Division of Critical Care Medicine, Department of Pediatrics, Northwestern University Feinberg School of Medicine, Ann and Robert H. Lurie Children's Hospital of Chicago, Chicago (B.M. Coates); the Division of Pediatric Critical Care Medicine, Department of Pediatrics, University of Alabama at Birmingham, Birmingham (M.K.); the Division of Pediatric Infectious Diseases, Department of Pediatrics, UHealth Holtz Children's Hospital, Miami (B.M. Chatani); and the Department of Pediatrics and Banner Children's at Diamond Children's Medical Center, University of Arizona, Tucson (K.V.T.).; Hume JR; From the Covid-19 Response Team, Centers for Disease Control and Prevention (A.M.P., S.M.O., M.W.T., L.D.Z., A.P.C., M.M.P.), the Center for Childhood Infections and Vaccines of Children's Healthcare of Atlanta and the Department of Pediatrics, Emory University School of Medicine (S.K.), and the Division of Critical Care Medicine, Department of Pediatrics, Emory University School of Medicine, Children's Healthcare of Atlanta (K.M.T.) - all in Atlanta; the Department of Anesthesiology, Critical Care, and Pain Medicine, Boston Children's Hospital (M.M.N., A.G.R.), and the Departments of Anaesthesia and Pediatrics, Harvard Medical School (A.G.R.) - both in Boston; the Division of Pediatric Infectious Diseases, Department of Pediatrics, Vanderbilt University Medical Center, Nashville (N.B.H.); the Department of Pediatrics, Baylor College of Medicine, Immunization Project, Texas Children's Hospital, Houston (J.A.B., L.C.S.), and the Department of Pediatrics, Division of Critical Care Medicine, University of Texas Southwestern, Children's Medical Center, Dallas (M.M.); the Division of Infectious Diseases, Children's Hospital Los Angeles and Departments of Pediatrics and Molecular Microbiology and Immunology, University of Southern California, Los Angeles (P.S.P.), the Division of Pediatric Hospital Medicine, UC San Diego-Rady Children's Hospital, San Diego (M.A.C.), the Division of Critical Care Medicine, UCSF Benioff Children's Hospital, Oakland (N.Z.C.), and the Department of Pediatrics, Divisions of Critical Care Medicine and Allergy, Immunology, and Bone Marrow Transplant, University of California, San Francisco, San Francisco (M.S.Z.) - all in California; Section of Pediatric Critical Care, Department of Pediatrics, Arkansas Children's Hospital, Little Rock (K.I.); the Division of Pediatric Critical Care Medicine, Nationwide Children's Hospital Columbus (K.E.B.), the Division of Critical Care Medicine, Department of Pediatrics, Akron Children's Hospital, Akron (R.A.N.), and the Department of Pediatrics, University of Cincinnati College of Medicine, Cincinnati Children's Hospital Medical Center, Cincinnati (M.A.S.) - all in Ohio; the Department of Pediatrics, Section of Critical Care Medicine, University of Colorado School of Medicine and Children's Hospital Colorado, Aurora (A.B.M.); the Department of Pediatrics, University of North Carolina at Chapel Hill Children's Hospital, Chapel Hill (T.C.W., S.P.S.); the Division of Pediatric Critical Care Medicine (E.H.M.) and the Department of Pediatrics (L.S.), Medical University of South Carolina, Charleston; the Division of Pediatric Infectious Diseases, Department of Pediatrics, Children's Mercy Kansas City, Kansas City, MO (J.E.S.); the Departments of Pediatrics and Microbiology, Division of Infectious Diseases, University of Mississippi Medical Center, Jackson (C.V.H.); the Department of Pediatrics, Division of Cardiology, Louisiana State University Health Sciences Center and Children's Hospital of New Orleans, New Orleans (T.T.B.); the Divisions of Pediatric Infectious Diseases and Pediatric Critical Care Medicine, Department of Pediatric and Adolescent Medicine, Mayo Clinic, Rochester (E.R.L.), and the Division of Pediatric Critical Care, University of Minnesota Masonic Children's Hospital, Minneapolis (J.R.H.) - both in Minnesota; the Division of Critical Care Medicine, Department of Anesthesiology and Critical Care, Children's Hospital of Philadelphia, Philadelphia (K.C.); the Ryan White Center for Pediatric Infectious Disease and Global Health, Department of Pediatrics, Indiana University School of Medicine, Indianapolis (S.S.B.); the Division of Pediatric Critical Care Medicine, Children's Hospital of Michigan, Central Michigan University, Detroit (S.M.H.), and the Division of Pediatric Critical Care Medicine, Department of Pediatrics, Mott Children's Hospital and University of Michigan, Ann Arbor (H.R.F.); the Division of Pediatric Critical Care, Department of Pediatrics, Children's Hospital and Medical Center, Omaha, NE (M.L.C.); the Division of Pediatric Critical Care, Department of Pediatrics, Cooperman Barnabas Medical Center, Livingston, NJ (S.J.G.); the Division of Critical Care Medicine, Department of Pediatrics, Northwestern University Feinberg School of Medicine, Ann and Robert H. Lurie Children's Hospital of Chicago, Chicago (B.M. Coates); the Division of Pediatric Critical Care Medicine, Department of Pediatrics, University of Alabama at Birmingham, Birmingham (M.K.); the Division of Pediatric Infectious Diseases, Department of Pediatrics, UHealth Holtz Children's Hospital, Miami (B.M. Chatani); and the Department of Pediatrics and Banner Children's at Diamond Children's Medical Center, University of Arizona, Tucson (K.V.T.).; Typpo KV; From the Covid-19 Response Team, Centers for Disease Control and Prevention (A.M.P., S.M.O., M.W.T., L.D.Z., A.P.C., M.M.P.), the Center for Childhood Infections and Vaccines of Children's Healthcare of Atlanta and the Department of Pediatrics, Emory University School of Medicine (S.K.), and the Division of Critical Care Medicine, Department of Pediatrics, Emory University School of Medicine, Children's Healthcare of Atlanta (K.M.T.) - all in Atlanta; the Department of Anesthesiology, Critical Care, and Pain Medicine, Boston Children's Hospital (M.M.N., A.G.R.), and the Departments of Anaesthesia and Pediatrics, Harvard Medical School (A.G.R.) - both in Boston; the Division of Pediatric Infectious Diseases, Department of Pediatrics, Vanderbilt University Medical Center, Nashville (N.B.H.); the Department of Pediatrics, Baylor College of Medicine, Immunization Project, Texas Children's Hospital, Houston (J.A.B., L.C.S.), and the Department of Pediatrics, Division of Critical Care Medicine, University of Texas Southwestern, Children's Medical Center, Dallas (M.M.); the Division of Infectious Diseases, Children's Hospital Los Angeles and Departments of Pediatrics and Molecular Microbiology and Immunology, University of Southern California, Los Angeles (P.S.P.), the Division of Pediatric Hospital Medicine, UC San Diego-Rady Children's Hospital, San Diego (M.A.C.), the Division of Critical Care Medicine, UCSF Benioff Children's Hospital, Oakland (N.Z.C.), and the Department of Pediatrics, Divisions of Critical Care Medicine and Allergy, Immunology, and Bone Marrow Transplant, University of California, San Francisco, San Francisco (M.S.Z.) - all in California; Section of Pediatric Critical Care, Department of Pediatrics, Arkansas Children's Hospital, Little Rock (K.I.); the Division of Pediatric Critical Care Medicine, Nationwide Children's Hospital Columbus (K.E.B.), the Division of Critical Care Medicine, Department of Pediatrics, Akron Children's Hospital, Akron (R.A.N.), and the Department of Pediatrics, University of Cincinnati College of Medicine, Cincinnati Children's Hospital Medical Center, Cincinnati (M.A.S.) - all in Ohio; the Department of Pediatrics, Section of Critical Care Medicine, University of Colorado School of Medicine and Children's Hospital Colorado, Aurora (A.B.M.); the Department of Pediatrics, University of North Carolina at Chapel Hill Children's Hospital, Chapel Hill (T.C.W., S.P.S.); the Division of Pediatric Critical Care Medicine (E.H.M.) and the Department of Pediatrics (L.S.), Medical University of South Carolina, Charleston; the Division of Pediatric Infectious Diseases, Department of Pediatrics, Children's Mercy Kansas City, Kansas City, MO (J.E.S.); the Departments of Pediatrics and Microbiology, Division of Infectious Diseases, University of Mississippi Medical Center, Jackson (C.V.H.); the Department of Pediatrics, Division of Cardiology, Louisiana State University Health Sciences Center and Children's Hospital of New Orleans, New Orleans (T.T.B.); the Divisions of Pediatric Infectious Diseases and Pediatric Critical Care Medicine, Department of Pediatric and Adolescent Medicine, Mayo Clinic, Rochester (E.R.L.), and the Division of Pediatric Critical Care, University of Minnesota Masonic Children's Hospital, Minneapolis (J.R.H.) - both in Minnesota; the Division of Critical Care Medicine, Department of Anesthesiology and Critical Care, Children's Hospital of Philadelphia, Philadelphia (K.C.); the Ryan White Center for Pediatric Infectious Disease and Global Health, Department of Pediatrics, Indiana University School of Medicine, Indianapolis (S.S.B.); the Division of Pediatric Critical Care Medicine, Children's Hospital of Michigan, Central Michigan University, Detroit (S.M.H.), and the Division of Pediatric Critical Care Medicine, Department of Pediatrics, Mott Children's Hospital and University of Michigan, Ann Arbor (H.R.F.); the Division of Pediatric Critical Care, Department of Pediatrics, Children's Hospital and Medical Center, Omaha, NE (M.L.C.); the Division of Pediatric Critical Care, Department of Pediatrics, Cooperman Barnabas Medical Center, Livingston, NJ (S.J.G.); the Division of Critical Care Medicine, Department of Pediatrics, Northwestern University Feinberg School of Medicine, Ann and Robert H. Lurie Children's Hospital of Chicago, Chicago (B.M. Coates); the Division of Pediatric Critical Care Medicine, Department of Pediatrics, University of Alabama at Birmingham, Birmingham (M.K.); the Division of Pediatric Infectious Diseases, Department of Pediatrics, UHealth Holtz Children's Hospital, Miami (B.M. Chatani); and the Department of Pediatrics and Banner Children's at Diamond Children's Medical Center, University of Arizona, Tucson (K.V.T.).; Maamari M; From the Covid-19 Response Team, Centers for Disease Control and Prevention (A.M.P., S.M.O., M.W.T., L.D.Z., A.P.C., M.M.P.), the Center for Childhood Infections and Vaccines of Children's Healthcare of Atlanta and the Department of Pediatrics, Emory University School of Medicine (S.K.), and the Division of Critical Care Medicine, Department of Pediatrics, Emory University School of Medicine, Children's Healthcare of Atlanta (K.M.T.) - all in Atlanta; the Department of Anesthesiology, Critical Care, and Pain Medicine, Boston Children's Hospital (M.M.N., A.G.R.), and the Departments of Anaesthesia and Pediatrics, Harvard Medical School (A.G.R.) - both in Boston; the Division of Pediatric Infectious Diseases, Department of Pediatrics, Vanderbilt University Medical Center, Nashville (N.B.H.); the Department of Pediatrics, Baylor College of Medicine, Immunization Project, Texas Children's Hospital, Houston (J.A.B., L.C.S.), and the Department of Pediatrics, Division of Critical Care Medicine, University of Texas Southwestern, Children's Medical Center, Dallas (M.M.); the Division of Infectious Diseases, Children's Hospital Los Angeles and Departments of Pediatrics and Molecular Microbiology and Immunology, University of Southern California, Los Angeles (P.S.P.), the Division of Pediatric Hospital Medicine, UC San Diego-Rady Children's Hospital, San Diego (M.A.C.), the Division of Critical Care Medicine, UCSF Benioff Children's Hospital, Oakland (N.Z.C.), and the Department of Pediatrics, Divisions of Critical Care Medicine and Allergy, Immunology, and Bone Marrow Transplant, University of California, San Francisco, San Francisco (M.S.Z.) - all in California; Section of Pediatric Critical Care, Department of Pediatrics, Arkansas Children's Hospital, Little Rock (K.I.); the Division of Pediatric Critical Care Medicine, Nationwide Children's Hospital Columbus (K.E.B.), the Division of Critical Care Medicine, Department of Pediatrics, Akron Children's Hospital, Akron (R.A.N.), and the Department of Pediatrics, University of Cincinnati College of Medicine, Cincinnati Children's Hospital Medical Center, Cincinnati (M.A.S.) - all in Ohio; the Department of Pediatrics, Section of Critical Care Medicine, University of Colorado School of Medicine and Children's Hospital Colorado, Aurora (A.B.M.); the Department of Pediatrics, University of North Carolina at Chapel Hill Children's Hospital, Chapel Hill (T.C.W., S.P.S.); the Division of Pediatric Critical Care Medicine (E.H.M.) and the Department of Pediatrics (L.S.), Medical University of South Carolina, Charleston; the Division of Pediatric Infectious Diseases, Department of Pediatrics, Children's Mercy Kansas City, Kansas City, MO (J.E.S.); the Departments of Pediatrics and Microbiology, Division of Infectious Diseases, University of Mississippi Medical Center, Jackson (C.V.H.); the Department of Pediatrics, Division of Cardiology, Louisiana State University Health Sciences Center and Children's Hospital of New Orleans, New Orleans (T.T.B.); the Divisions of Pediatric Infectious Diseases and Pediatric Critical Care Medicine, Department of Pediatric and Adolescent Medicine, Mayo Clinic, Rochester (E.R.L.), and the Division of Pediatric Critical Care, University of Minnesota Masonic Children's Hospital, Minneapolis (J.R.H.) - both in Minnesota; the Division of Critical Care Medicine, Department of Anesthesiology and Critical Care, Children's Hospital of Philadelphia, Philadelphia (K.C.); the Ryan White Center for Pediatric Infectious Disease and Global Health, Department of Pediatrics, Indiana University School of Medicine, Indianapolis (S.S.B.); the Division of Pediatric Critical Care Medicine, Children's Hospital of Michigan, Central Michigan University, Detroit (S.M.H.), and the Division of Pediatric Critical Care Medicine, Department of Pediatrics, Mott Children's Hospital and University of Michigan, Ann Arbor (H.R.F.); the Division of Pediatric Critical Care, Department of Pediatrics, Children's Hospital and Medical Center, Omaha, NE (M.L.C.); the Division of Pediatric Critical Care, Department of Pediatrics, Cooperman Barnabas Medical Center, Livingston, NJ (S.J.G.); the Division of Critical Care Medicine, Department of Pediatrics, Northwestern University Feinberg School of Medicine, Ann and Robert H. Lurie Children's Hospital of Chicago, Chicago (B.M. Coates); the Division of Pediatric Critical Care Medicine, Department of Pediatrics, University of Alabama at Birmingham, Birmingham (M.K.); the Division of Pediatric Infectious Diseases, Department of Pediatrics, UHealth Holtz Children's Hospital, Miami (B.M. Chatani); and the Department of Pediatrics and Banner Children's at Diamond Children's Medical Center, University of Arizona, Tucson (K.V.T.).; Flori HR; From the Covid-19 Response Team, Centers for Disease Control and Prevention (A.M.P., S.M.O., M.W.T., L.D.Z., A.P.C., M.M.P.), the Center for Childhood Infections and Vaccines of Children's Healthcare of Atlanta and the Department of Pediatrics, Emory University School of Medicine (S.K.), and the Division of Critical Care Medicine, Department of Pediatrics, Emory University School of Medicine, Children's Healthcare of Atlanta (K.M.T.) - all in Atlanta; the Department of Anesthesiology, Critical Care, and Pain Medicine, Boston Children's Hospital (M.M.N., A.G.R.), and the Departments of Anaesthesia and Pediatrics, Harvard Medical School (A.G.R.) - both in Boston; the Division of Pediatric Infectious Diseases, Department of Pediatrics, Vanderbilt University Medical Center, Nashville (N.B.H.); the Department of Pediatrics, Baylor College of Medicine, Immunization Project, Texas Children's Hospital, Houston (J.A.B., L.C.S.), and the Department of Pediatrics, Division of Critical Care Medicine, University of Texas Southwestern, Children's Medical Center, Dallas (M.M.); the Division of Infectious Diseases, Children's Hospital Los Angeles and Departments of Pediatrics and Molecular Microbiology and Immunology, University of Southern California, Los Angeles (P.S.P.), the Division of Pediatric Hospital Medicine, UC San Diego-Rady Children's Hospital, San Diego (M.A.C.), the Division of Critical Care Medicine, UCSF Benioff Children's Hospital, Oakland (N.Z.C.), and the Department of Pediatrics, Divisions of Critical Care Medicine and Allergy, Immunology, and Bone Marrow Transplant, University of California, San Francisco, San Francisco (M.S.Z.) - all in California; Section of Pediatric Critical Care, Department of Pediatrics, Arkansas Children's Hospital, Little Rock (K.I.); the Division of Pediatric Critical Care Medicine, Nationwide Children's Hospital Columbus (K.E.B.), the Division of Critical Care Medicine, Department of Pediatrics, Akron Children's Hospital, Akron (R.A.N.), and the Department of Pediatrics, University of Cincinnati College of Medicine, Cincinnati Children's Hospital Medical Center, Cincinnati (M.A.S.) - all in Ohio; the Department of Pediatrics, Section of Critical Care Medicine, University of Colorado School of Medicine and Children's Hospital Colorado, Aurora (A.B.M.); the Department of Pediatrics, University of North Carolina at Chapel Hill Children's Hospital, Chapel Hill (T.C.W., S.P.S.); the Division of Pediatric Critical Care Medicine (E.H.M.) and the Department of Pediatrics (L.S.), Medical University of South Carolina, Charleston; the Division of Pediatric Infectious Diseases, Department of Pediatrics, Children's Mercy Kansas City, Kansas City, MO (J.E.S.); the Departments of Pediatrics and Microbiology, Division of Infectious Diseases, University of Mississippi Medical Center, Jackson (C.V.H.); the Department of Pediatrics, Division of Cardiology, Louisiana State University Health Sciences Center and Children's Hospital of New Orleans, New Orleans (T.T.B.); the Divisions of Pediatric Infectious Diseases and Pediatric Critical Care Medicine, Department of Pediatric and Adolescent Medicine, Mayo Clinic, Rochester (E.R.L.), and the Division of Pediatric Critical Care, University of Minnesota Masonic Children's Hospital, Minneapolis (J.R.H.) - both in Minnesota; the Division of Critical Care Medicine, Department of Anesthesiology and Critical Care, Children's Hospital of Philadelphia, Philadelphia (K.C.); the Ryan White Center for Pediatric Infectious Disease and Global Health, Department of Pediatrics, Indiana University School of Medicine, Indianapolis (S.S.B.); the Division of Pediatric Critical Care Medicine, Children's Hospital of Michigan, Central Michigan University, Detroit (S.M.H.), and the Division of Pediatric Critical Care Medicine, Department of Pediatrics, Mott Children's Hospital and University of Michigan, Ann Arbor (H.R.F.); the Division of Pediatric Critical Care, Department of Pediatrics, Children's Hospital and Medical Center, Omaha, NE (M.L.C.); the Division of Pediatric Critical Care, Department of Pediatrics, Cooperman Barnabas Medical Center, Livingston, NJ (S.J.G.); the Division of Critical Care Medicine, Department of Pediatrics, Northwestern University Feinberg School of Medicine, Ann and Robert H. Lurie Children's Hospital of Chicago, Chicago (B.M. Coates); the Division of Pediatric Critical Care Medicine, Department of Pediatrics, University of Alabama at Birmingham, Birmingham (M.K.); the Division of Pediatric Infectious Diseases, Department of Pediatrics, UHealth Holtz Children's Hospital, Miami (B.M. Chatani); and the Department of Pediatrics and Banner Children's at Diamond Children's Medical Center, University of Arizona, Tucson (K.V.T.).; Tenforde MW; From the Covid-19 Response Team, Centers for Disease Control and Prevention (A.M.P., S.M.O., M.W.T., L.D.Z., A.P.C., M.M.P.), the Center for Childhood Infections and Vaccines of Children's Healthcare of Atlanta and the Department of Pediatrics, Emory University School of Medicine (S.K.), and the Division of Critical Care Medicine, Department of Pediatrics, Emory University School of Medicine, Children's Healthcare of Atlanta (K.M.T.) - all in Atlanta; the Department of Anesthesiology, Critical Care, and Pain Medicine, Boston Children's Hospital (M.M.N., A.G.R.), and the Departments of Anaesthesia and Pediatrics, Harvard Medical School (A.G.R.) - both in Boston; the Division of Pediatric Infectious Diseases, Department of Pediatrics, Vanderbilt University Medical Center, Nashville (N.B.H.); the Department of Pediatrics, Baylor College of Medicine, Immunization Project, Texas Children's Hospital, Houston (J.A.B., L.C.S.), and the Department of Pediatrics, Division of Critical Care Medicine, University of Texas Southwestern, Children's Medical Center, Dallas (M.M.); the Division of Infectious Diseases, Children's Hospital Los Angeles and Departments of Pediatrics and Molecular Microbiology and Immunology, University of Southern California, Los Angeles (P.S.P.), the Division of Pediatric Hospital Medicine, UC San Diego-Rady Children's Hospital, San Diego (M.A.C.), the Division of Critical Care Medicine, UCSF Benioff Children's Hospital, Oakland (N.Z.C.), and the Department of Pediatrics, Divisions of Critical Care Medicine and Allergy, Immunology, and Bone Marrow Transplant, University of California, San Francisco, San Francisco (M.S.Z.) - all in California; Section of Pediatric Critical Care, Department of Pediatrics, Arkansas Children's Hospital, Little Rock (K.I.); the Division of Pediatric Critical Care Medicine, Nationwide Children's Hospital Columbus (K.E.B.), the Division of Critical Care Medicine, Department of Pediatrics, Akron Children's Hospital, Akron (R.A.N.), and the Department of Pediatrics, University of Cincinnati College of Medicine, Cincinnati Children's Hospital Medical Center, Cincinnati (M.A.S.) - all in Ohio; the Department of Pediatrics, Section of Critical Care Medicine, University of Colorado School of Medicine and Children's Hospital Colorado, Aurora (A.B.M.); the Department of Pediatrics, University of North Carolina at Chapel Hill Children's Hospital, Chapel Hill (T.C.W., S.P.S.); the Division of Pediatric Critical Care Medicine (E.H.M.) and the Department of Pediatrics (L.S.), Medical University of South Carolina, Charleston; the Division of Pediatric Infectious Diseases, Department of Pediatrics, Children's Mercy Kansas City, Kansas City, MO (J.E.S.); the Departments of Pediatrics and Microbiology, Division of Infectious Diseases, University of Mississippi Medical Center, Jackson (C.V.H.); the Department of Pediatrics, Division of Cardiology, Louisiana State University Health Sciences Center and Children's Hospital of New Orleans, New Orleans (T.T.B.); the Divisions of Pediatric Infectious Diseases and Pediatric Critical Care Medicine, Department of Pediatric and Adolescent Medicine, Mayo Clinic, Rochester (E.R.L.), and the Division of Pediatric Critical Care, University of Minnesota Masonic Children's Hospital, Minneapolis (J.R.H.) - both in Minnesota; the Division of Critical Care Medicine, Department of Anesthesiology and Critical Care, Children's Hospital of Philadelphia, Philadelphia (K.C.); the Ryan White Center for Pediatric Infectious Disease and Global Health, Department of Pediatrics, Indiana University School of Medicine, Indianapolis (S.S.B.); the Division of Pediatric Critical Care Medicine, Children's Hospital of Michigan, Central Michigan University, Detroit (S.M.H.), and the Division of Pediatric Critical Care Medicine, Department of Pediatrics, Mott Children's Hospital and University of Michigan, Ann Arbor (H.R.F.); the Division of Pediatric Critical Care, Department of Pediatrics, Children's Hospital and Medical Center, Omaha, NE (M.L.C.); the Division of Pediatric Critical Care, Department of Pediatrics, Cooperman Barnabas Medical Center, Livingston, NJ (S.J.G.); the Division of Critical Care Medicine, Department of Pediatrics, Northwestern University Feinberg School of Medicine, Ann and Robert H. Lurie Children's Hospital of Chicago, Chicago (B.M. Coates); the Division of Pediatric Critical Care Medicine, Department of Pediatrics, University of Alabama at Birmingham, Birmingham (M.K.); the Division of Pediatric Infectious Diseases, Department of Pediatrics, UHealth Holtz Children's Hospital, Miami (B.M. Chatani); and the Department of Pediatrics and Banner Children's at Diamond Children's Medical Center, University of Arizona, Tucson (K.V.T.).; Zambrano LD; From the Covid-19 Response Team, Centers for Disease Control and Prevention (A.M.P., S.M.O., M.W.T., L.D.Z., A.P.C., M.M.P.), the Center for Childhood Infections and Vaccines of Children's Healthcare of Atlanta and the Department of Pediatrics, Emory University School of Medicine (S.K.), and the Division of Critical Care Medicine, Department of Pediatrics, Emory University School of Medicine, Children's Healthcare of Atlanta (K.M.T.) - all in Atlanta; the Department of Anesthesiology, Critical Care, and Pain Medicine, Boston Children's Hospital (M.M.N., A.G.R.), and the Departments of Anaesthesia and Pediatrics, Harvard Medical School (A.G.R.) - both in Boston; the Division of Pediatric Infectious Diseases, Department of Pediatrics, Vanderbilt University Medical Center, Nashville (N.B.H.); the Department of Pediatrics, Baylor College of Medicine, Immunization Project, Texas Children's Hospital, Houston (J.A.B., L.C.S.), and the Department of Pediatrics, Division of Critical Care Medicine, University of Texas Southwestern, Children's Medical Center, Dallas (M.M.); the Division of Infectious Diseases, Children's Hospital Los Angeles and Departments of Pediatrics and Molecular Microbiology and Immunology, University of Southern California, Los Angeles (P.S.P.), the Division of Pediatric Hospital Medicine, UC San Diego-Rady Children's Hospital, San Diego (M.A.C.), the Division of Critical Care Medicine, UCSF Benioff Children's Hospital, Oakland (N.Z.C.), and the Department of Pediatrics, Divisions of Critical Care Medicine and Allergy, Immunology, and Bone Marrow Transplant, University of California, San Francisco, San Francisco (M.S.Z.) - all in California; Section of Pediatric Critical Care, Department of Pediatrics, Arkansas Children's Hospital, Little Rock (K.I.); the Division of Pediatric Critical Care Medicine, Nationwide Children's Hospital Columbus (K.E.B.), the Division of Critical Care Medicine, Department of Pediatrics, Akron Children's Hospital, Akron (R.A.N.), and the Department of Pediatrics, University of Cincinnati College of Medicine, Cincinnati Children's Hospital Medical Center, Cincinnati (M.A.S.) - all in Ohio; the Department of Pediatrics, Section of Critical Care Medicine, University of Colorado School of Medicine and Children's Hospital Colorado, Aurora (A.B.M.); the Department of Pediatrics, University of North Carolina at Chapel Hill Children's Hospital, Chapel Hill (T.C.W., S.P.S.); the Division of Pediatric Critical Care Medicine (E.H.M.) and the Department of Pediatrics (L.S.), Medical University of South Carolina, Charleston; the Division of Pediatric Infectious Diseases, Department of Pediatrics, Children's Mercy Kansas City, Kansas City, MO (J.E.S.); the Departments of Pediatrics and Microbiology, Division of Infectious Diseases, University of Mississippi Medical Center, Jackson (C.V.H.); the Department of Pediatrics, Division of Cardiology, Louisiana State University Health Sciences Center and Children's Hospital of New Orleans, New Orleans (T.T.B.); the Divisions of Pediatric Infectious Diseases and Pediatric Critical Care Medicine, Department of Pediatric and Adolescent Medicine, Mayo Clinic, Rochester (E.R.L.), and the Division of Pediatric Critical Care, University of Minnesota Masonic Children's Hospital, Minneapolis (J.R.H.) - both in Minnesota; the Division of Critical Care Medicine, Department of Anesthesiology and Critical Care, Children's Hospital of Philadelphia, Philadelphia (K.C.); the Ryan White Center for Pediatric Infectious Disease and Global Health, Department of Pediatrics, Indiana University School of Medicine, Indianapolis (S.S.B.); the Division of Pediatric Critical Care Medicine, Children's Hospital of Michigan, Central Michigan University, Detroit (S.M.H.), and the Division of Pediatric Critical Care Medicine, Department of Pediatrics, Mott Children's Hospital and University of Michigan, Ann Arbor (H.R.F.); the Division of Pediatric Critical Care, Department of Pediatrics, Children's Hospital and Medical Center, Omaha, NE (M.L.C.); the Division of Pediatric Critical Care, Department of Pediatrics, Cooperman Barnabas Medical Center, Livingston, NJ (S.J.G.); the Division of Critical Care Medicine, Department of Pediatrics, Northwestern University Feinberg School of Medicine, Ann and Robert H. Lurie Children's Hospital of Chicago, Chicago (B.M. Coates); the Division of Pediatric Critical Care Medicine, Department of Pediatrics, University of Alabama at Birmingham, Birmingham (M.K.); the Division of Pediatric Infectious Diseases, Department of Pediatrics, UHealth Holtz Children's Hospital, Miami (B.M. Chatani); and the Department of Pediatrics and Banner Children's at Diamond Children's Medical Center, University of Arizona, Tucson (K.V.T.).; Campbell AP; From the Covid-19 Response Team, Centers for Disease Control and Prevention (A.M.P., S.M.O., M.W.T., L.D.Z., A.P.C., M.M.P.), the Center for Childhood Infections and Vaccines of Children's Healthcare of Atlanta and the Department of Pediatrics, Emory University School of Medicine (S.K.), and the Division of Critical Care Medicine, Department of Pediatrics, Emory University School of Medicine, Children's Healthcare of Atlanta (K.M.T.) - all in Atlanta; the Department of Anesthesiology, Critical Care, and Pain Medicine, Boston Children's Hospital (M.M.N., A.G.R.), and the Departments of Anaesthesia and Pediatrics, Harvard Medical School (A.G.R.) - both in Boston; the Division of Pediatric Infectious Diseases, Department of Pediatrics, Vanderbilt University Medical Center, Nashville (N.B.H.); the Department of Pediatrics, Baylor College of Medicine, Immunization Project, Texas Children's Hospital, Houston (J.A.B., L.C.S.), and the Department of Pediatrics, Division of Critical Care Medicine, University of Texas Southwestern, Children's Medical Center, Dallas (M.M.); the Division of Infectious Diseases, Children's Hospital Los Angeles and Departments of Pediatrics and Molecular Microbiology and Immunology, University of Southern California, Los Angeles (P.S.P.), the Division of Pediatric Hospital Medicine, UC San Diego-Rady Children's Hospital, San Diego (M.A.C.), the Division of Critical Care Medicine, UCSF Benioff Children's Hospital, Oakland (N.Z.C.), and the Department of Pediatrics, Divisions of Critical Care Medicine and Allergy, Immunology, and Bone Marrow Transplant, University of California, San Francisco, San Francisco (M.S.Z.) - all in California; Section of Pediatric Critical Care, Department of Pediatrics, Arkansas Children's Hospital, Little Rock (K.I.); the Division of Pediatric Critical Care Medicine, Nationwide Children's Hospital Columbus (K.E.B.), the Division of Critical Care Medicine, Department of Pediatrics, Akron Children's Hospital, Akron (R.A.N.), and the Department of Pediatrics, University of Cincinnati College of Medicine, Cincinnati Children's Hospital Medical Center, Cincinnati (M.A.S.) - all in Ohio; the Department of Pediatrics, Section of Critical Care Medicine, University of Colorado School of Medicine and Children's Hospital Colorado, Aurora (A.B.M.); the Department of Pediatrics, University of North Carolina at Chapel Hill Children's Hospital, Chapel Hill (T.C.W., S.P.S.); the Division of Pediatric Critical Care Medicine (E.H.M.) and the Department of Pediatrics (L.S.), Medical University of South Carolina, Charleston; the Division of Pediatric Infectious Diseases, Department of Pediatrics, Children's Mercy Kansas City, Kansas City, MO (J.E.S.); the Departments of Pediatrics and Microbiology, Division of Infectious Diseases, University of Mississippi Medical Center, Jackson (C.V.H.); the Department of Pediatrics, Division of Cardiology, Louisiana State University Health Sciences Center and Children's Hospital of New Orleans, New Orleans (T.T.B.); the Divisions of Pediatric Infectious Diseases and Pediatric Critical Care Medicine, Department of Pediatric and Adolescent Medicine, Mayo Clinic, Rochester (E.R.L.), and the Division of Pediatric Critical Care, University of Minnesota Masonic Children's Hospital, Minneapolis (J.R.H.) - both in Minnesota; the Division of Critical Care Medicine, Department of Anesthesiology and Critical Care, Children's Hospital of Philadelphia, Philadelphia (K.C.); the Ryan White Center for Pediatric Infectious Disease and Global Health, Department of Pediatrics, Indiana University School of Medicine, Indianapolis (S.S.B.); the Division of Pediatric Critical Care Medicine, Children's Hospital of Michigan, Central Michigan University, Detroit (S.M.H.), and the Division of Pediatric Critical Care Medicine, Department of Pediatrics, Mott Children's Hospital and University of Michigan, Ann Arbor (H.R.F.); the Division of Pediatric Critical Care, Department of Pediatrics, Children's Hospital and Medical Center, Omaha, NE (M.L.C.); the Division of Pediatric Critical Care, Department of Pediatrics, Cooperman Barnabas Medical Center, Livingston, NJ (S.J.G.); the Division of Critical Care Medicine, Department of Pediatrics, Northwestern University Feinberg School of Medicine, Ann and Robert H. Lurie Children's Hospital of Chicago, Chicago (B.M. Coates); the Division of Pediatric Critical Care Medicine, Department of Pediatrics, University of Alabama at Birmingham, Birmingham (M.K.); the Division of Pediatric Infectious Diseases, Department of Pediatrics, UHealth Holtz Children's Hospital, Miami (B.M. Chatani); and the Department of Pediatrics and Banner Children's at Diamond Children's Medical Center, University of Arizona, Tucson (K.V.T.).; Patel MM; From the Covid-19 Response Team, Centers for Disease Control and Prevention (A.M.P., S.M.O., M.W.T., L.D.Z., A.P.C., M.M.P.), the Center for Childhood Infections and Vaccines of Children's Healthcare of Atlanta and the Department of Pediatrics, Emory University School of Medicine (S.K.), and the Division of Critical Care Medicine, Department of Pediatrics, Emory University School of Medicine, Children's Healthcare of Atlanta (K.M.T.) - all in Atlanta; the Department of Anesthesiology, Critical Care, and Pain Medicine, Boston Children's Hospital (M.M.N., A.G.R.), and the Departments of Anaesthesia and Pediatrics, Harvard Medical School (A.G.R.) - both in Boston; the Division of Pediatric Infectious Diseases, Department of Pediatrics, Vanderbilt University Medical Center, Nashville (N.B.H.); the Department of Pediatrics, Baylor College of Medicine, Immunization Project, Texas Children's Hospital, Houston (J.A.B., L.C.S.), and the Department of Pediatrics, Division of Critical Care Medicine, University of Texas Southwestern, Children's Medical Center, Dallas (M.M.); the Division of Infectious Diseases, Children's Hospital Los Angeles and Departments of Pediatrics and Molecular Microbiology and Immunology, University of Southern California, Los Angeles (P.S.P.), the Division of Pediatric Hospital Medicine, UC San Diego-Rady Children's Hospital, San Diego (M.A.C.), the Division of Critical Care Medicine, UCSF Benioff Children's Hospital, Oakland (N.Z.C.), and the Department of Pediatrics, Divisions of Critical Care Medicine and Allergy, Immunology, and Bone Marrow Transplant, University of California, San Francisco, San Francisco (M.S.Z.) - all in California; Section of Pediatric Critical Care, Department of Pediatrics, Arkansas Children's Hospital, Little Rock (K.I.); the Division of Pediatric Critical Care Medicine, Nationwide Children's Hospital Columbus (K.E.B.), the Division of Critical Care Medicine, Department of Pediatrics, Akron Children's Hospital, Akron (R.A.N.), and the Department of Pediatrics, University of Cincinnati College of Medicine, Cincinnati Children's Hospital Medical Center, Cincinnati (M.A.S.) - all in Ohio; the Department of Pediatrics, Section of Critical Care Medicine, University of Colorado School of Medicine and Children's Hospital Colorado, Aurora (A.B.M.); the Department of Pediatrics, University of North Carolina at Chapel Hill Children's Hospital, Chapel Hill (T.C.W., S.P.S.); the Division of Pediatric Critical Care Medicine (E.H.M.) and the Department of Pediatrics (L.S.), Medical University of South Carolina, Charleston; the Division of Pediatric Infectious Diseases, Department of Pediatrics, Children's Mercy Kansas City, Kansas City, MO (J.E.S.); the Departments of Pediatrics and Microbiology, Division of Infectious Diseases, University of Mississippi Medical Center, Jackson (C.V.H.); the Department of Pediatrics, Division of Cardiology, Louisiana State University Health Sciences Center and Children's Hospital of New Orleans, New Orleans (T.T.B.); the Divisions of Pediatric Infectious Diseases and Pediatric Critical Care Medicine, Department of Pediatric and Adolescent Medicine, Mayo Clinic, Rochester (E.R.L.), and the Division of Pediatric Critical Care, University of Minnesota Masonic Children's Hospital, Minneapolis (J.R.H.) - both in Minnesota; the Division of Critical Care Medicine, Department of Anesthesiology and Critical Care, Children's Hospital of Philadelphia, Philadelphia (K.C.); the Ryan White Center for Pediatric Infectious Disease and Global Health, Department of Pediatrics, Indiana University School of Medicine, Indianapolis (S.S.B.); the Division of Pediatric Critical Care Medicine, Children's Hospital of Michigan, Central Michigan University, Detroit (S.M.H.), and the Division of Pediatric Critical Care Medicine, Department of Pediatrics, Mott Children's Hospital and University of Michigan, Ann Arbor (H.R.F.); the Division of Pediatric Critical Care, Department of Pediatrics, Children's Hospital and Medical Center, Omaha, NE (M.L.C.); the Division of Pediatric Critical Care, Department of Pediatrics, Cooperman Barnabas Medical Center, Livingston, NJ (S.J.G.); the Division of Critical Care Medicine, Department of Pediatrics, Northwestern University Feinberg School of Medicine, Ann and Robert H. Lurie Children's Hospital of Chicago, Chicago (B.M. Coates); the Division of Pediatric Critical Care Medicine, Department of Pediatrics, University of Alabama at Birmingham, Birmingham (M.K.); the Division of Pediatric Infectious Diseases, Department of Pediatrics, UHealth Holtz Children's Hospital, Miami (B.M. Chatani); and the Department of Pediatrics and Banner Children's at Diamond Children's Medical Center, University of Arizona, Tucson (K.V.T.).; Randolph AG; From the Covid-19 Response Team, Centers for Disease Control and Prevention (A.M.P., S.M.O., M.W.T., L.D.Z., A.P.C., M.M.P.), the Center for Childhood Infections and Vaccines of Children's Healthcare of Atlanta and the Department of Pediatrics, Emory University School of Medicine (S.K.), and the Division of Critical Care Medicine, Department of Pediatrics, Emory University School of Medicine, Children's Healthcare of Atlanta (K.M.T.) - all in Atlanta; the Department of Anesthesiology, Critical Care, and Pain Medicine, Boston Children's Hospital (M.M.N., A.G.R.), and the Departments of Anaesthesia and Pediatrics, Harvard Medical School (A.G.R.) - both in Boston; the Division of Pediatric Infectious Diseases, Department of Pediatrics, Vanderbilt University Medical Center, Nashville (N.B.H.); the Department of Pediatrics, Baylor College of Medicine, Immunization Project, Texas Children's Hospital, Houston (J.A.B., L.C.S.), and the Department of Pediatrics, Division of Critical Care Medicine, University of Texas Southwestern, Children's Medical Center, Dallas (M.M.); the Division of Infectious Diseases, Children's Hospital Los Angeles and Departments of Pediatrics and Molecular Microbiology and Immunology, University of Southern California, Los Angeles (P.S.P.), the Division of Pediatric Hospital Medicine, UC San Diego-Rady Children's Hospital, San Diego (M.A.C.), the Division of Critical Care Medicine, UCSF Benioff Children's Hospital, Oakland (N.Z.C.), and the Department of Pediatrics, Divisions of Critical Care Medicine and Allergy, Immunology, and Bone Marrow Transplant, University of California, San Francisco, San Francisco (M.S.Z.) - all in California; Section of Pediatric Critical Care, Department of Pediatrics, Arkansas Children's Hospital, Little Rock (K.I.); the Division of Pediatric Critical Care Medicine, Nationwide Children's Hospital Columbus (K.E.B.), the Division of Critical Care Medicine, Department of Pediatrics, Akron Children's Hospital, Akron (R.A.N.), and the Department of Pediatrics, University of Cincinnati College of Medicine, Cincinnati Children's Hospital Medical Center, Cincinnati (M.A.S.) - all in Ohio; the Department of Pediatrics, Section of Critical Care Medicine, University of Colorado School of Medicine and Children's Hospital Colorado, Aurora (A.B.M.); the Department of Pediatrics, University of North Carolina at Chapel Hill Children's Hospital, Chapel Hill (T.C.W., S.P.S.); the Division of Pediatric Critical Care Medicine (E.H.M.) and the Department of Pediatrics (L.S.), Medical University of South Carolina, Charleston; the Division of Pediatric Infectious Diseases, Department of Pediatrics, Children's Mercy Kansas City, Kansas City, MO (J.E.S.); the Departments of Pediatrics and Microbiology, Division of Infectious Diseases, University of Mississippi Medical Center, Jackson (C.V.H.); the Department of Pediatrics, Division of Cardiology, Louisiana State University Health Sciences Center and Children's Hospital of New Orleans, New Orleans (T.T.B.); the Divisions of Pediatric Infectious Diseases and Pediatric Critical Care Medicine, Department of Pediatric and Adolescent Medicine, Mayo Clinic, Rochester (E.R.L.), and the Division of Pediatric Critical Care, University of Minnesota Masonic Children's Hospital, Minneapolis (J.R.H.) - both in Minnesota; the Division of Critical Care Medicine, Department of Anesthesiology and Critical Care, Children's Hospital of Philadelphia, Philadelphia (K.C.); the Ryan White Center for Pediatric Infectious Disease and Global Health, Department of Pediatrics, Indiana University School of Medicine, Indianapolis (S.S.B.); the Division of Pediatric Critical Care Medicine, Children's Hospital of Michigan, Central Michigan University, Detroit (S.M.H.), and the Division of Pediatric Critical Care Medicine, Department of Pediatrics, Mott Children's Hospital and University of Michigan, Ann Arbor (H.R.F.); the Division of Pediatric Critical Care, Department of Pediatrics, Children's Hospital and Medical Center, Omaha, NE (M.L.C.); the Division of Pediatric Critical Care, Department of Pediatrics, Cooperman Barnabas Medical Center, Livingston, NJ (S.J.G.); the Division of Critical Care Medicine, Department of Pediatrics, Northwestern University Feinberg School of Medicine, Ann and Robert H. Lurie Children's Hospital of Chicago, Chicago (B.M. Coates); the Division of Pediatric Critical Care Medicine, Department of Pediatrics, University of Alabama at Birmingham, Birmingham (M.K.); the Division of Pediatric Infectious Diseases, Department of Pediatrics, UHealth Holtz Children's Hospital, Miami (B.M. Chatani); and the Department of Pediatrics and Banner Children's at Diamond Children's Medical Center, University of Arizona, Tucson (K.V.T.).

Publisher: Massachusetts Medical Society Country of Publication: United States NLM ID: 0255562 Publication Model: Print-Electronic Cited Medium: Internet ISSN: 1533-4406 (Electronic) Linking ISSN: 00284793 NLM ISO Abbreviation: N Engl J Med Subsets: MEDLINE

Sahni LC; Department of Pediatrics, Baylor College of Medicine, Immunization Project, Texas Children's Hospital, Houston, Texas, USA.; Price AM; CDC COVID-19 Response Team, Centers for Disease Control and Prevention, Atlanta, Georgia, USA.; Olson SM; CDC COVID-19 Response Team, Centers for Disease Control and Prevention, Atlanta, Georgia, USA.; Newhams MM; Department of Anesthesiology, Critical Care, and Pain Medicine, Boston Children's Hospital, Boston, Massachusetts, USA.; Pannaraj PS; Division of Infectious Diseases, Children's Hospital Los Angeles and Departments of Pediatrics and Molecular Microbiology and Immunology, University of Southern California, Los Angeles, California, USA.; Maddux AB; Department of Pediatrics, Section of Critical Care Medicine, University of Colorado School of Medicine and Children's Hospital Colorado, Aurora, Colorado, USA.; Halasa NB; Division of Pediatric Infectious Diseases, Department of Pediatrics, Vanderbilt University Medical Center, Nashville, Tennessee, USA.; Bline KE; Division of Pediatric Critical Care Medicine, Nationwide Children's Hospital Columbus, Columbus, Ohio, USA.; Cameron MA; Division of Pediatric Hospital Medicine, UC San Diego-Rady Children's Hospital, San Diego, California, USA.; Schwartz SP; Department of Pediatrics, University of North Carolina at Chapel Hill Children's Hospital, Chapel Hill, North Carolina, USA.; Walker TC; Department of Pediatrics, University of North Carolina at Chapel Hill Children's Hospital, Chapel Hill, North Carolina, USA.; Irby K; Section of Pediatric Critical Care, Department of Pediatrics, Arkansas Children's Hospital, Little Rock, Arkansas, USA.; Chiotos K; Division of Critical Care Medicine, Department of Anesthesiology and Critical Care, Children's Hospital of Philadelphia, Philadelphia, Pennsylvania, USA.; Nofziger RA; Division of Critical Care Medicine, Department of Pediatrics, Akron Children's Hospital, Akron, Ohio, USA.; Mack EH; Division of Pediatric Critical Care Medicine, Medical University of South Carolina, Charleston, South Carolina, USA.; Smallcomb L; Department of Pediatrics, Medical University of South Carolina, Charleston, South Carolina, USA.; Bradford TT; Department of Pediatrics, Division of Cardiology, Louisiana State University Health Sciences Center and Children's Hospital of New Orleans, New Orleans, Los Angeles, USA.; Kamidani S; The Center for Childhood Infections and Vaccines of Children's Healthcare of Atlanta and the Department of Pediatrics, Emory University School of Medicine, Atlanta, Georgia, USA.; Tarquinio KM; Division of Critical Care Medicine, Department of Pediatrics, Emory University School of Medicine, Children's Healthcare of Atlanta, Atlanta, Georgia, USA.; Cvijanovich NZ; Division of Critical Care Medicine, UCSF Benioff Children's Hospital Oakland, Oakland, California, USA.; Schuster JE; Division of Pediatric Infectious Diseases, Department of Pediatrics, Children's Mercy Kansas City, Kansas City, Missouri, USA.; Bhumbra SS; The Ryan White Center for Pediatric Infectious Disease and Global Health, Department of Pediatrics, Indiana University School of Medicine, Indianapolis, Indiana, USA.; Levy ER; Divisions of Pediatric Infectious Diseases and Pediatric Critical Care Medicine, Department of Pediatric and Adolescent Medicine, Mayo Clinic, Rochester, Minnesota, USA.; Hobbs CV; Department of Pediatrics, Department of Microbiology, Division of Infectious Diseases, University of Mississippi Medical Center, Jackson, Mississippi, USA.; Cullimore ML; Division of Pediatric Critical Care, Department of Pediatrics, Children's Hospital and Medical Center, Omaha, Nebraska, USA.; Coates BM; Division of Critical Care Medicine, Department of Pediatrics, Northwestern University Feinberg School of Medicine, Ann & Robert H. Lurie Children's Hospital of Chicago, Chicago, Illinois, USA.; Heidemann SM; Division of Pediatric Critical Care Medicine, Children's Hospital of MI, Central Michigan University, Detroit, Michigan, USA.; Gertz SJ; Division of Pediatric Critical Care, Department of Pediatrics, Cooperman Barnabas Medical Center, Livingston, New Jersey, USA.; Kong M; Division of Pediatric Critical Care Medicine, Department of Pediatrics, University of Alabama at Birmingham, Birmingham, Alabama, USA.; Flori HR; Division of Pediatric Critical Care Medicine, Department of Pediatrics, Mott Children's Hospital and University of Michigan, Ann Arbor, Michigan, USA.; Staat MA; Department of Pediatrics, University of Cincinnati College of Medicine, Cincinnati Children's Hospital Medical Center, Cincinnati, Ohio, USA.; Zinter MS; Department of Pediatrics, Divisions of Critical Care Medicine and Allergy, Immunology, and Bone Marrow Transplant, University of California San Francisco, San Francisco, California, USA.; Hume JR; Division of Pediatric Critical Care, University of Minnesota Masonic Children's Hospital, Minneapolis, Minnesota, USA.; Chatani BM; Division of Pediatric Infectious Diseases, Department of Pediatrics, UHealth/Holtz Children's Hospital, Miami, Florida, USA.; Gaspers MG; University of Arizona, Diamond Children's Banner Children's Medical Center, Tucson, Arizona, USA.; Maamari M; Department of Pediatrics, Division of Critical Care Medicine, University of Texas Southwestern, Children's Medical Center Dallas, Dallas, Texas, USA.; Randolph AG; Department of Anesthesiology, Critical Care, and Pain Medicine, Boston Children's Hospital, Boston, Massachusetts, USA.; Departments of Anaesthesia and Pediatrics, Harvard Medical School, Boston, Massachusetts, USA.; Patel MM; CDC COVID-19 Response Team, Centers for Disease Control and Prevention, Atlanta, Georgia, USA.; Boom JA; Department of Pediatrics, Baylor College of Medicine, Immunization Project, Texas Children's Hospital, Houston, Texas, USA.

Publisher: Oxford University Press Country of Publication: England NLM ID: 101586049 Publication Model: Print Cited Medium: Internet ISSN: 2048-7207 (Electronic) Linking ISSN: 20487193 NLM ISO Abbreviation: J Pediatric Infect Dis Soc Subsets: MEDLINE

Bline KE; The Abigail Wexner Research Institute at Nationwide Children's Hospital, Columbus, OH.; Division of Critical Care Medicine, Nationwide Children's Hospital, Columbus, OH.; Muszynski JA; The Abigail Wexner Research Institute at Nationwide Children's Hospital, Columbus, OH.; Division of Critical Care Medicine, Nationwide Children's Hospital, Columbus, OH.; Guess AJ; The Abigail Wexner Research Institute at Nationwide Children's Hospital, Columbus, OH.; Menocha S; The Abigail Wexner Research Institute at Nationwide Children's Hospital, Columbus, OH.; Moore-Clingenpeel MD; The Abigail Wexner Research Institute at Nationwide Children's Hospital, Columbus, OH.; Division of Critical Care Medicine, Nationwide Children's Hospital, Columbus, OH.; Popelka JK; The Abigail Wexner Research Institute at Nationwide Children's Hospital, Columbus, OH.; Hensley JM; The Abigail Wexner Research Institute at Nationwide Children's Hospital, Columbus, OH.; Steele LM; The Abigail Wexner Research Institute at Nationwide Children's Hospital, Columbus, OH.; Goldthwaite IC; The Abigail Wexner Research Institute at Nationwide Children's Hospital, Columbus, OH.; Jedreski KJ; The Abigail Wexner Research Institute at Nationwide Children's Hospital, Columbus, OH.; Hall MW; The Abigail Wexner Research Institute at Nationwide Children's Hospital, Columbus, OH.; Division of Critical Care Medicine, Nationwide Children's Hospital, Columbus, OH.

Publisher: Lippincott Williams & Wilkins Country of Publication: United States NLM ID: 100954653 Publication Model: Print-Electronic Cited Medium: Internet ISSN: 1529-7535 (Print) Linking ISSN: 15297535 NLM ISO Abbreviation: Pediatr Crit Care Med Subsets: MEDLINE

Olson SM; From the Covid-19 Response Team, Centers for Disease Control and Prevention (S.M.O., A.M.P., L.D.Z., A.P.C., M.M.P.), and the Center for Childhood Infections and Vaccines of Children's Healthcare of Atlanta and the Department of Pediatrics, Emory University School of Medicine (S.K.) - both in Atlanta; the Department of Anesthesiology, Critical Care, and Pain Medicine, Boston Children's Hospital (M.M.N., A.G.R.), and the Departments of Anaesthesia and Pediatrics, Harvard Medical School (A.G.R.) - both in Boston; the Division of Pediatric Infectious Diseases, Department of Pediatrics, Vanderbilt University Medical Center, Nashville (N.B.H.); the Department of Pediatrics, Baylor College of Medicine, Immunization Project, Texas Children's Hospital, Houston (J.A.B., L.C.S.), and the Department of Pediatrics, Division of Critical Care Medicine, University of Texas Southwestern, Children's Medical Center Dallas, Dallas (M.M.); the Division of Infectious Diseases, Children's Hospital Los Angeles and Departments of Pediatrics and Molecular Microbiology and Immunology, University of Southern California, Los Angeles (P.S.P.), the Division of Pediatric Hospital Medicine, UC San Diego-Rady Children's Hospital, San Diego (M.A.C.), the Division of Critical Care Medicine, UCSF Benioff Children's Hospital Oakland (N.Z.C.), and the Department of Pediatrics, Divisions of Critical Care Medicine and Allergy, Immunology, and Bone Marrow Transplant, University of California, San Francisco, San Francisco (M.S.Z.) - all in California; Section of Pediatric Critical Care, Department of Pediatrics, Arkansas Children's Hospital, Little Rock (K.I.); the Department of Pediatrics, University of North Carolina at Chapel Hill Children's Hospital, Chapel Hill (T.C.W., S.P.S.); the Department of Pediatrics, Section of Critical Care Medicine, University of Colorado School of Medicine and Children's Hospital Colorado, Aurora (A.B.M.); the Division of Pediatric Critical Care Medicine, Medical University of South Carolina, Charleston (E.H.M.); the Department of Pediatrics, Division of Cardiology, Louisiana State University Health Sciences Center and Children's Hospital of New Orleans, New Orleans (T.T.B.); the Division of Pediatric Infectious Diseases, Department of Pediatrics, Children's Mercy Kansas City, Kansas City, MO (J.E.S.); the Division of Critical Care Medicine, Department of Pediatrics, Akron Children's Hospital, Akron (R.A.N.), the Department of Pediatrics, University of Cincinnati College of Medicine, Cincinnati Children's Hospital Medical Center, Cincinnati (M.A.S.), and the Division of Pediatric Critical Care Medicine, Nationwide Children's Hospital Columbus, Columbus (K.E.B.) - all in Ohio; the Division of Critical Care Medicine, Department of Anesthesiology and Critical Care, Children's Hospital of Philadelphia, Philadelphia (K.C.); the Division of Pediatric Critical Care, Department of Pediatrics, Children's Hospital and Medical Center, Omaha, NE (M.L.C.); the Division of Pediatric Critical Care, Department of Pediatrics, Saint Barnabas Medical Center, Livingston, NJ (S.J.G.); the Divisions of Pediatric Infectious Diseases and Pediatric Critical Care Medicine, Department of Pediatric and Adolescent Medicine, Mayo Clinic, Rochester (E.R.L.), and the Division of Pediatric Critical Care, University of Minnesota Masonic Children's Hospital, Minneapolis (J.R.H.) - both in Minnesota; the Division of Pediatric Critical Care Medicine, Department of Pediatrics, University of Alabama at Birmingham, Birmingham (M.K.), the Division of Pediatric Infectious Diseases, Department of Pediatrics, UHealth/Holtz Children's Hospital, Miami (B.M.C.); the Ryan White Center for Pediatric Infectious Disease and Global Health, Department of Pediatrics, Indiana University School of Medicine, Indianapolis (S.S.B.); University of Arizona, Diamond Children's Banner Children's Medical Center, Tucson (M.G.G.); the Department of Pediatrics, Department of Microbiology, Division of Infectious Diseases, University of Mississippi Medical Center, Jackson (C.V.H.); the Department of Pediatrics, Children's Hospital of Michigan, Central Michigan University, Detroit (S.M.H.), and the Division of Pediatric Critical Care Medicine, Department of Pediatrics, Mott Children's Hospital and University of Michigan, Ann Arbor (H.R.F.); and the Division of Critical Care Medicine, Department of Pediatrics, Northwestern University Feinberg School of Medicine, Ann and Robert H. Lurie Children's Hospital of Chicago, Chicago (K.N.M.).; Newhams MM; From the Covid-19 Response Team, Centers for Disease Control and Prevention (S.M.O., A.M.P., L.D.Z., A.P.C., M.M.P.), and the Center for Childhood Infections and Vaccines of Children's Healthcare of Atlanta and the Department of Pediatrics, Emory University School of Medicine (S.K.) - both in Atlanta; the Department of Anesthesiology, Critical Care, and Pain Medicine, Boston Children's Hospital (M.M.N., A.G.R.), and the Departments of Anaesthesia and Pediatrics, Harvard Medical School (A.G.R.) - both in Boston; the Division of Pediatric Infectious Diseases, Department of Pediatrics, Vanderbilt University Medical Center, Nashville (N.B.H.); the Department of Pediatrics, Baylor College of Medicine, Immunization Project, Texas Children's Hospital, Houston (J.A.B., L.C.S.), and the Department of Pediatrics, Division of Critical Care Medicine, University of Texas Southwestern, Children's Medical Center Dallas, Dallas (M.M.); the Division of Infectious Diseases, Children's Hospital Los Angeles and Departments of Pediatrics and Molecular Microbiology and Immunology, University of Southern California, Los Angeles (P.S.P.), the Division of Pediatric Hospital Medicine, UC San Diego-Rady Children's Hospital, San Diego (M.A.C.), the Division of Critical Care Medicine, UCSF Benioff Children's Hospital Oakland (N.Z.C.), and the Department of Pediatrics, Divisions of Critical Care Medicine and Allergy, Immunology, and Bone Marrow Transplant, University of California, San Francisco, San Francisco (M.S.Z.) - all in California; Section of Pediatric Critical Care, Department of Pediatrics, Arkansas Children's Hospital, Little Rock (K.I.); the Department of Pediatrics, University of North Carolina at Chapel Hill Children's Hospital, Chapel Hill (T.C.W., S.P.S.); the Department of Pediatrics, Section of Critical Care Medicine, University of Colorado School of Medicine and Children's Hospital Colorado, Aurora (A.B.M.); the Division of Pediatric Critical Care Medicine, Medical University of South Carolina, Charleston (E.H.M.); the Department of Pediatrics, Division of Cardiology, Louisiana State University Health Sciences Center and Children's Hospital of New Orleans, New Orleans (T.T.B.); the Division of Pediatric Infectious Diseases, Department of Pediatrics, Children's Mercy Kansas City, Kansas City, MO (J.E.S.); the Division of Critical Care Medicine, Department of Pediatrics, Akron Children's Hospital, Akron (R.A.N.), the Department of Pediatrics, University of Cincinnati College of Medicine, Cincinnati Children's Hospital Medical Center, Cincinnati (M.A.S.), and the Division of Pediatric Critical Care Medicine, Nationwide Children's Hospital Columbus, Columbus (K.E.B.) - all in Ohio; the Division of Critical Care Medicine, Department of Anesthesiology and Critical Care, Children's Hospital of Philadelphia, Philadelphia (K.C.); the Division of Pediatric Critical Care, Department of Pediatrics, Children's Hospital and Medical Center, Omaha, NE (M.L.C.); the Division of Pediatric Critical Care, Department of Pediatrics, Saint Barnabas Medical Center, Livingston, NJ (S.J.G.); the Divisions of Pediatric Infectious Diseases and Pediatric Critical Care Medicine, Department of Pediatric and Adolescent Medicine, Mayo Clinic, Rochester (E.R.L.), and the Division of Pediatric Critical Care, University of Minnesota Masonic Children's Hospital, Minneapolis (J.R.H.) - both in Minnesota; the Division of Pediatric Critical Care Medicine, Department of Pediatrics, University of Alabama at Birmingham, Birmingham (M.K.), the Division of Pediatric Infectious Diseases, Department of Pediatrics, UHealth/Holtz Children's Hospital, Miami (B.M.C.); the Ryan White Center for Pediatric Infectious Disease and Global Health, Department of Pediatrics, Indiana University School of Medicine, Indianapolis (S.S.B.); University of Arizona, Diamond Children's Banner Children's Medical Center, Tucson (M.G.G.); the Department of Pediatrics, Department of Microbiology, Division of Infectious Diseases, University of Mississippi Medical Center, Jackson (C.V.H.); the Department of Pediatrics, Children's Hospital of Michigan, Central Michigan University, Detroit (S.M.H.), and the Division of Pediatric Critical Care Medicine, Department of Pediatrics, Mott Children's Hospital and University of Michigan, Ann Arbor (H.R.F.); and the Division of Critical Care Medicine, Department of Pediatrics, Northwestern University Feinberg School of Medicine, Ann and Robert H. Lurie Children's Hospital of Chicago, Chicago (K.N.M.).; Halasa NB; From the Covid-19 Response Team, Centers for Disease Control and Prevention (S.M.O., A.M.P., L.D.Z., A.P.C., M.M.P.), and the Center for Childhood Infections and Vaccines of Children's Healthcare of Atlanta and the Department of Pediatrics, Emory University School of Medicine (S.K.) - both in Atlanta; the Department of Anesthesiology, Critical Care, and Pain Medicine, Boston Children's Hospital (M.M.N., A.G.R.), and the Departments of Anaesthesia and Pediatrics, Harvard Medical School (A.G.R.) - both in Boston; the Division of Pediatric Infectious Diseases, Department of Pediatrics, Vanderbilt University Medical Center, Nashville (N.B.H.); the Department of Pediatrics, Baylor College of Medicine, Immunization Project, Texas Children's Hospital, Houston (J.A.B., L.C.S.), and the Department of Pediatrics, Division of Critical Care Medicine, University of Texas Southwestern, Children's Medical Center Dallas, Dallas (M.M.); the Division of Infectious Diseases, Children's Hospital Los Angeles and Departments of Pediatrics and Molecular Microbiology and Immunology, University of Southern California, Los Angeles (P.S.P.), the Division of Pediatric Hospital Medicine, UC San Diego-Rady Children's Hospital, San Diego (M.A.C.), the Division of Critical Care Medicine, UCSF Benioff Children's Hospital Oakland (N.Z.C.), and the Department of Pediatrics, Divisions of Critical Care Medicine and Allergy, Immunology, and Bone Marrow Transplant, University of California, San Francisco, San Francisco (M.S.Z.) - all in California; Section of Pediatric Critical Care, Department of Pediatrics, Arkansas Children's Hospital, Little Rock (K.I.); the Department of Pediatrics, University of North Carolina at Chapel Hill Children's Hospital, Chapel Hill (T.C.W., S.P.S.); the Department of Pediatrics, Section of Critical Care Medicine, University of Colorado School of Medicine and Children's Hospital Colorado, Aurora (A.B.M.); the Division of Pediatric Critical Care Medicine, Medical University of South Carolina, Charleston (E.H.M.); the Department of Pediatrics, Division of Cardiology, Louisiana State University Health Sciences Center and Children's Hospital of New Orleans, New Orleans (T.T.B.); the Division of Pediatric Infectious Diseases, Department of Pediatrics, Children's Mercy Kansas City, Kansas City, MO (J.E.S.); the Division of Critical Care Medicine, Department of Pediatrics, Akron Children's Hospital, Akron (R.A.N.), the Department of Pediatrics, University of Cincinnati College of Medicine, Cincinnati Children's Hospital Medical Center, Cincinnati (M.A.S.), and the Division of Pediatric Critical Care Medicine, Nationwide Children's Hospital Columbus, Columbus (K.E.B.) - all in Ohio; the Division of Critical Care Medicine, Department of Anesthesiology and Critical Care, Children's Hospital of Philadelphia, Philadelphia (K.C.); the Division of Pediatric Critical Care, Department of Pediatrics, Children's Hospital and Medical Center, Omaha, NE (M.L.C.); the Division of Pediatric Critical Care, Department of Pediatrics, Saint Barnabas Medical Center, Livingston, NJ (S.J.G.); the Divisions of Pediatric Infectious Diseases and Pediatric Critical Care Medicine, Department of Pediatric and Adolescent Medicine, Mayo Clinic, Rochester (E.R.L.), and the Division of Pediatric Critical Care, University of Minnesota Masonic Children's Hospital, Minneapolis (J.R.H.) - both in Minnesota; the Division of Pediatric Critical Care Medicine, Department of Pediatrics, University of Alabama at Birmingham, Birmingham (M.K.), the Division of Pediatric Infectious Diseases, Department of Pediatrics, UHealth/Holtz Children's Hospital, Miami (B.M.C.); the Ryan White Center for Pediatric Infectious Disease and Global Health, Department of Pediatrics, Indiana University School of Medicine, Indianapolis (S.S.B.); University of Arizona, Diamond Children's Banner Children's Medical Center, Tucson (M.G.G.); the Department of Pediatrics, Department of Microbiology, Division of Infectious Diseases, University of Mississippi Medical Center, Jackson (C.V.H.); the Department of Pediatrics, Children's Hospital of Michigan, Central Michigan University, Detroit (S.M.H.), and the Division of Pediatric Critical Care Medicine, Department of Pediatrics, Mott Children's Hospital and University of Michigan, Ann Arbor (H.R.F.); and the Division of Critical Care Medicine, Department of Pediatrics, Northwestern University Feinberg School of Medicine, Ann and Robert H. Lurie Children's Hospital of Chicago, Chicago (K.N.M.).; Price AM; From the Covid-19 Response Team, Centers for Disease Control and Prevention (S.M.O., A.M.P., L.D.Z., A.P.C., M.M.P.), and the Center for Childhood Infections and Vaccines of Children's Healthcare of Atlanta and the Department of Pediatrics, Emory University School of Medicine (S.K.) - both in Atlanta; the Department of Anesthesiology, Critical Care, and Pain Medicine, Boston Children's Hospital (M.M.N., A.G.R.), and the Departments of Anaesthesia and Pediatrics, Harvard Medical School (A.G.R.) - both in Boston; the Division of Pediatric Infectious Diseases, Department of Pediatrics, Vanderbilt University Medical Center, Nashville (N.B.H.); the Department of Pediatrics, Baylor College of Medicine, Immunization Project, Texas Children's Hospital, Houston (J.A.B., L.C.S.), and the Department of Pediatrics, Division of Critical Care Medicine, University of Texas Southwestern, Children's Medical Center Dallas, Dallas (M.M.); the Division of Infectious Diseases, Children's Hospital Los Angeles and Departments of Pediatrics and Molecular Microbiology and Immunology, University of Southern California, Los Angeles (P.S.P.), the Division of Pediatric Hospital Medicine, UC San Diego-Rady Children's Hospital, San Diego (M.A.C.), the Division of Critical Care Medicine, UCSF Benioff Children's Hospital Oakland (N.Z.C.), and the Department of Pediatrics, Divisions of Critical Care Medicine and Allergy, Immunology, and Bone Marrow Transplant, University of California, San Francisco, San Francisco (M.S.Z.) - all in California; Section of Pediatric Critical Care, Department of Pediatrics, Arkansas Children's Hospital, Little Rock (K.I.); the Department of Pediatrics, University of North Carolina at Chapel Hill Children's Hospital, Chapel Hill (T.C.W., S.P.S.); the Department of Pediatrics, Section of Critical Care Medicine, University of Colorado School of Medicine and Children's Hospital Colorado, Aurora (A.B.M.); the Division of Pediatric Critical Care Medicine, Medical University of South Carolina, Charleston (E.H.M.); the Department of Pediatrics, Division of Cardiology, Louisiana State University Health Sciences Center and Children's Hospital of New Orleans, New Orleans (T.T.B.); the Division of Pediatric Infectious Diseases, Department of Pediatrics, Children's Mercy Kansas City, Kansas City, MO (J.E.S.); the Division of Critical Care Medicine, Department of Pediatrics, Akron Children's Hospital, Akron (R.A.N.), the Department of Pediatrics, University of Cincinnati College of Medicine, Cincinnati Children's Hospital Medical Center, Cincinnati (M.A.S.), and the Division of Pediatric Critical Care Medicine, Nationwide Children's Hospital Columbus, Columbus (K.E.B.) - all in Ohio; the Division of Critical Care Medicine, Department of Anesthesiology and Critical Care, Children's Hospital of Philadelphia, Philadelphia (K.C.); the Division of Pediatric Critical Care, Department of Pediatrics, Children's Hospital and Medical Center, Omaha, NE (M.L.C.); the Division of Pediatric Critical Care, Department of Pediatrics, Saint Barnabas Medical Center, Livingston, NJ (S.J.G.); the Divisions of Pediatric Infectious Diseases and Pediatric Critical Care Medicine, Department of Pediatric and Adolescent Medicine, Mayo Clinic, Rochester (E.R.L.), and the Division of Pediatric Critical Care, University of Minnesota Masonic Children's Hospital, Minneapolis (J.R.H.) - both in Minnesota; the Division of Pediatric Critical Care Medicine, Department of Pediatrics, University of Alabama at Birmingham, Birmingham (M.K.), the Division of Pediatric Infectious Diseases, Department of Pediatrics, UHealth/Holtz Children's Hospital, Miami (B.M.C.); the Ryan White Center for Pediatric Infectious Disease and Global Health, Department of Pediatrics, Indiana University School of Medicine, Indianapolis (S.S.B.); University of Arizona, Diamond Children's Banner Children's Medical Center, Tucson (M.G.G.); the Department of Pediatrics, Department of Microbiology, Division of Infectious Diseases, University of Mississippi Medical Center, Jackson (C.V.H.); the Department of Pediatrics, Children's Hospital of Michigan, Central Michigan University, Detroit (S.M.H.), and the Division of Pediatric Critical Care Medicine, Department of Pediatrics, Mott Children's Hospital and University of Michigan, Ann Arbor (H.R.F.); and the Division of Critical Care Medicine, Department of Pediatrics, Northwestern University Feinberg School of Medicine, Ann and Robert H. Lurie Children's Hospital of Chicago, Chicago (K.N.M.).; Boom JA; From the Covid-19 Response Team, Centers for Disease Control and Prevention (S.M.O., A.M.P., L.D.Z., A.P.C., M.M.P.), and the Center for Childhood Infections and Vaccines of Children's Healthcare of Atlanta and the Department of Pediatrics, Emory University School of Medicine (S.K.) - both in Atlanta; the Department of Anesthesiology, Critical Care, and Pain Medicine, Boston Children's Hospital (M.M.N., A.G.R.), and the Departments of Anaesthesia and Pediatrics, Harvard Medical School (A.G.R.) - both in Boston; the Division of Pediatric Infectious Diseases, Department of Pediatrics, Vanderbilt University Medical Center, Nashville (N.B.H.); the Department of Pediatrics, Baylor College of Medicine, Immunization Project, Texas Children's Hospital, Houston (J.A.B., L.C.S.), and the Department of Pediatrics, Division of Critical Care Medicine, University of Texas Southwestern, Children's Medical Center Dallas, Dallas (M.M.); the Division of Infectious Diseases, Children's Hospital Los Angeles and Departments of Pediatrics and Molecular Microbiology and Immunology, University of Southern California, Los Angeles (P.S.P.), the Division of Pediatric Hospital Medicine, UC San Diego-Rady Children's Hospital, San Diego (M.A.C.), the Division of Critical Care Medicine, UCSF Benioff Children's Hospital Oakland (N.Z.C.), and the Department of Pediatrics, Divisions of Critical Care Medicine and Allergy, Immunology, and Bone Marrow Transplant, University of California, San Francisco, San Francisco (M.S.Z.) - all in California; Section of Pediatric Critical Care, Department of Pediatrics, Arkansas Children's Hospital, Little Rock (K.I.); the Department of Pediatrics, University of North Carolina at Chapel Hill Children's Hospital, Chapel Hill (T.C.W., S.P.S.); the Department of Pediatrics, Section of Critical Care Medicine, University of Colorado School of Medicine and Children's Hospital Colorado, Aurora (A.B.M.); the Division of Pediatric Critical Care Medicine, Medical University of South Carolina, Charleston (E.H.M.); the Department of Pediatrics, Division of Cardiology, Louisiana State University Health Sciences Center and Children's Hospital of New Orleans, New Orleans (T.T.B.); the Division of Pediatric Infectious Diseases, Department of Pediatrics, Children's Mercy Kansas City, Kansas City, MO (J.E.S.); the Division of Critical Care Medicine, Department of Pediatrics, Akron Children's Hospital, Akron (R.A.N.), the Department of Pediatrics, University of Cincinnati College of Medicine, Cincinnati Children's Hospital Medical Center, Cincinnati (M.A.S.), and the Division of Pediatric Critical Care Medicine, Nationwide Children's Hospital Columbus, Columbus (K.E.B.) - all in Ohio; the Division of Critical Care Medicine, Department of Anesthesiology and Critical Care, Children's Hospital of Philadelphia, Philadelphia (K.C.); the Division of Pediatric Critical Care, Department of Pediatrics, Children's Hospital and Medical Center, Omaha, NE (M.L.C.); the Division of Pediatric Critical Care, Department of Pediatrics, Saint Barnabas Medical Center, Livingston, NJ (S.J.G.); the Divisions of Pediatric Infectious Diseases and Pediatric Critical Care Medicine, Department of Pediatric and Adolescent Medicine, Mayo Clinic, Rochester (E.R.L.), and the Division of Pediatric Critical Care, University of Minnesota Masonic Children's Hospital, Minneapolis (J.R.H.) - both in Minnesota; the Division of Pediatric Critical Care Medicine, Department of Pediatrics, University of Alabama at Birmingham, Birmingham (M.K.), the Division of Pediatric Infectious Diseases, Department of Pediatrics, UHealth/Holtz Children's Hospital, Miami (B.M.C.); the Ryan White Center for Pediatric Infectious Disease and Global Health, Department of Pediatrics, Indiana University School of Medicine, Indianapolis (S.S.B.); University of Arizona, Diamond Children's Banner Children's Medical Center, Tucson (M.G.G.); the Department of Pediatrics, Department of Microbiology, Division of Infectious Diseases, University of Mississippi Medical Center, Jackson (C.V.H.); the Department of Pediatrics, Children's Hospital of Michigan, Central Michigan University, Detroit (S.M.H.), and the Division of Pediatric Critical Care Medicine, Department of Pediatrics, Mott Children's Hospital and University of Michigan, Ann Arbor (H.R.F.); and the Division of Critical Care Medicine, Department of Pediatrics, Northwestern University Feinberg School of Medicine, Ann and Robert H. Lurie Children's Hospital of Chicago, Chicago (K.N.M.).; Sahni LC; From the Covid-19 Response Team, Centers for Disease Control and Prevention (S.M.O., A.M.P., L.D.Z., A.P.C., M.M.P.), and the Center for Childhood Infections and Vaccines of Children's Healthcare of Atlanta and the Department of Pediatrics, Emory University School of Medicine (S.K.) - both in Atlanta; the Department of Anesthesiology, Critical Care, and Pain Medicine, Boston Children's Hospital (M.M.N., A.G.R.), and the Departments of Anaesthesia and Pediatrics, Harvard Medical School (A.G.R.) - both in Boston; the Division of Pediatric Infectious Diseases, Department of Pediatrics, Vanderbilt University Medical Center, Nashville (N.B.H.); the Department of Pediatrics, Baylor College of Medicine, Immunization Project, Texas Children's Hospital, Houston (J.A.B., L.C.S.), and the Department of Pediatrics, Division of Critical Care Medicine, University of Texas Southwestern, Children's Medical Center Dallas, Dallas (M.M.); the Division of Infectious Diseases, Children's Hospital Los Angeles and Departments of Pediatrics and Molecular Microbiology and Immunology, University of Southern California, Los Angeles (P.S.P.), the Division of Pediatric Hospital Medicine, UC San Diego-Rady Children's Hospital, San Diego (M.A.C.), the Division of Critical Care Medicine, UCSF Benioff Children's Hospital Oakland (N.Z.C.), and the Department of Pediatrics, Divisions of Critical Care Medicine and Allergy, Immunology, and Bone Marrow Transplant, University of California, San Francisco, San Francisco (M.S.Z.) - all in California; Section of Pediatric Critical Care, Department of Pediatrics, Arkansas Children's Hospital, Little Rock (K.I.); the Department of Pediatrics, University of North Carolina at Chapel Hill Children's Hospital, Chapel Hill (T.C.W., S.P.S.); the Department of Pediatrics, Section of Critical Care Medicine, University of Colorado School of Medicine and Children's Hospital Colorado, Aurora (A.B.M.); the Division of Pediatric Critical Care Medicine, Medical University of South Carolina, Charleston (E.H.M.); the Department of Pediatrics, Division of Cardiology, Louisiana State University Health Sciences Center and Children's Hospital of New Orleans, New Orleans (T.T.B.); the Division of Pediatric Infectious Diseases, Department of Pediatrics, Children's Mercy Kansas City, Kansas City, MO (J.E.S.); the Division of Critical Care Medicine, Department of Pediatrics, Akron Children's Hospital, Akron (R.A.N.), the Department of Pediatrics, University of Cincinnati College of Medicine, Cincinnati Children's Hospital Medical Center, Cincinnati (M.A.S.), and the Division of Pediatric Critical Care Medicine, Nationwide Children's Hospital Columbus, Columbus (K.E.B.) - all in Ohio; the Division of Critical Care Medicine, Department of Anesthesiology and Critical Care, Children's Hospital of Philadelphia, Philadelphia (K.C.); the Division of Pediatric Critical Care, Department of Pediatrics, Children's Hospital and Medical Center, Omaha, NE (M.L.C.); the Division of Pediatric Critical Care, Department of Pediatrics, Saint Barnabas Medical Center, Livingston, NJ (S.J.G.); the Divisions of Pediatric Infectious Diseases and Pediatric Critical Care Medicine, Department of Pediatric and Adolescent Medicine, Mayo Clinic, Rochester (E.R.L.), and the Division of Pediatric Critical Care, University of Minnesota Masonic Children's Hospital, Minneapolis (J.R.H.) - both in Minnesota; the Division of Pediatric Critical Care Medicine, Department of Pediatrics, University of Alabama at Birmingham, Birmingham (M.K.), the Division of Pediatric Infectious Diseases, Department of Pediatrics, UHealth/Holtz Children's Hospital, Miami (B.M.C.); the Ryan White Center for Pediatric Infectious Disease and Global Health, Department of Pediatrics, Indiana University School of Medicine, Indianapolis (S.S.B.); University of Arizona, Diamond Children's Banner Children's Medical Center, Tucson (M.G.G.); the Department of Pediatrics, Department of Microbiology, Division of Infectious Diseases, University of Mississippi Medical Center, Jackson (C.V.H.); the Department of Pediatrics, Children's Hospital of Michigan, Central Michigan University, Detroit (S.M.H.), and the Division of Pediatric Critical Care Medicine, Department of Pediatrics, Mott Children's Hospital and University of Michigan, Ann Arbor (H.R.F.); and the Division of Critical Care Medicine, Department of Pediatrics, Northwestern University Feinberg School of Medicine, Ann and Robert H. Lurie Children's Hospital of Chicago, Chicago (K.N.M.).; Pannaraj PS; From the Covid-19 Response Team, Centers for Disease Control and Prevention (S.M.O., A.M.P., L.D.Z., A.P.C., M.M.P.), and the Center for Childhood Infections and Vaccines of Children's Healthcare of Atlanta and the Department of Pediatrics, Emory University School of Medicine (S.K.) - both in Atlanta; the Department of Anesthesiology, Critical Care, and Pain Medicine, Boston Children's Hospital (M.M.N., A.G.R.), and the Departments of Anaesthesia and Pediatrics, Harvard Medical School (A.G.R.) - both in Boston; the Division of Pediatric Infectious Diseases, Department of Pediatrics, Vanderbilt University Medical Center, Nashville (N.B.H.); the Department of Pediatrics, Baylor College of Medicine, Immunization Project, Texas Children's Hospital, Houston (J.A.B., L.C.S.), and the Department of Pediatrics, Division of Critical Care Medicine, University of Texas Southwestern, Children's Medical Center Dallas, Dallas (M.M.); the Division of Infectious Diseases, Children's Hospital Los Angeles and Departments of Pediatrics and Molecular Microbiology and Immunology, University of Southern California, Los Angeles (P.S.P.), the Division of Pediatric Hospital Medicine, UC San Diego-Rady Children's Hospital, San Diego (M.A.C.), the Division of Critical Care Medicine, UCSF Benioff Children's Hospital Oakland (N.Z.C.), and the Department of Pediatrics, Divisions of Critical Care Medicine and Allergy, Immunology, and Bone Marrow Transplant, University of California, San Francisco, San Francisco (M.S.Z.) - all in California; Section of Pediatric Critical Care, Department of Pediatrics, Arkansas Children's Hospital, Little Rock (K.I.); the Department of Pediatrics, University of North Carolina at Chapel Hill Children's Hospital, Chapel Hill (T.C.W., S.P.S.); the Department of Pediatrics, Section of Critical Care Medicine, University of Colorado School of Medicine and Children's Hospital Colorado, Aurora (A.B.M.); the Division of Pediatric Critical Care Medicine, Medical University of South Carolina, Charleston (E.H.M.); the Department of Pediatrics, Division of Cardiology, Louisiana State University Health Sciences Center and Children's Hospital of New Orleans, New Orleans (T.T.B.); the Division of Pediatric Infectious Diseases, Department of Pediatrics, Children's Mercy Kansas City, Kansas City, MO (J.E.S.); the Division of Critical Care Medicine, Department of Pediatrics, Akron Children's Hospital, Akron (R.A.N.), the Department of Pediatrics, University of Cincinnati College of Medicine, Cincinnati Children's Hospital Medical Center, Cincinnati (M.A.S.), and the Division of Pediatric Critical Care Medicine, Nationwide Children's Hospital Columbus, Columbus (K.E.B.) - all in Ohio; the Division of Critical Care Medicine, Department of Anesthesiology and Critical Care, Children's Hospital of Philadelphia, Philadelphia (K.C.); the Division of Pediatric Critical Care, Department of Pediatrics, Children's Hospital and Medical Center, Omaha, NE (M.L.C.); the Division of Pediatric Critical Care, Department of Pediatrics, Saint Barnabas Medical Center, Livingston, NJ (S.J.G.); the Divisions of Pediatric Infectious Diseases and Pediatric Critical Care Medicine, Department of Pediatric and Adolescent Medicine, Mayo Clinic, Rochester (E.R.L.), and the Division of Pediatric Critical Care, University of Minnesota Masonic Children's Hospital, Minneapolis (J.R.H.) - both in Minnesota; the Division of Pediatric Critical Care Medicine, Department of Pediatrics, University of Alabama at Birmingham, Birmingham (M.K.), the Division of Pediatric Infectious Diseases, Department of Pediatrics, UHealth/Holtz Children's Hospital, Miami (B.M.C.); the Ryan White Center for Pediatric Infectious Disease and Global Health, Department of Pediatrics, Indiana University School of Medicine, Indianapolis (S.S.B.); University of Arizona, Diamond Children's Banner Children's Medical Center, Tucson (M.G.G.); the Department of Pediatrics, Department of Microbiology, Division of Infectious Diseases, University of Mississippi Medical Center, Jackson (C.V.H.); the Department of Pediatrics, Children's Hospital of Michigan, Central Michigan University, Detroit (S.M.H.), and the Division of Pediatric Critical Care Medicine, Department of Pediatrics, Mott Children's Hospital and University of Michigan, Ann Arbor (H.R.F.); and the Division of Critical Care Medicine, Department of Pediatrics, Northwestern University Feinberg School of Medicine, Ann and Robert H. Lurie Children's Hospital of Chicago, Chicago (K.N.M.).; Irby K; From the Covid-19 Response Team, Centers for Disease Control and Prevention (S.M.O., A.M.P., L.D.Z., A.P.C., M.M.P.), and the Center for Childhood Infections and Vaccines of Children's Healthcare of Atlanta and the Department of Pediatrics, Emory University School of Medicine (S.K.) - both in Atlanta; the Department of Anesthesiology, Critical Care, and Pain Medicine, Boston Children's Hospital (M.M.N., A.G.R.), and the Departments of Anaesthesia and Pediatrics, Harvard Medical School (A.G.R.) - both in Boston; the Division of Pediatric Infectious Diseases, Department of Pediatrics, Vanderbilt University Medical Center, Nashville (N.B.H.); the Department of Pediatrics, Baylor College of Medicine, Immunization Project, Texas Children's Hospital, Houston (J.A.B., L.C.S.), and the Department of Pediatrics, Division of Critical Care Medicine, University of Texas Southwestern, Children's Medical Center Dallas, Dallas (M.M.); the Division of Infectious Diseases, Children's Hospital Los Angeles and Departments of Pediatrics and Molecular Microbiology and Immunology, University of Southern California, Los Angeles (P.S.P.), the Division of Pediatric Hospital Medicine, UC San Diego-Rady Children's Hospital, San Diego (M.A.C.), the Division of Critical Care Medicine, UCSF Benioff Children's Hospital Oakland (N.Z.C.), and the Department of Pediatrics, Divisions of Critical Care Medicine and Allergy, Immunology, and Bone Marrow Transplant, University of California, San Francisco, San Francisco (M.S.Z.) - all in California; Section of Pediatric Critical Care, Department of Pediatrics, Arkansas Children's Hospital, Little Rock (K.I.); the Department of Pediatrics, University of North Carolina at Chapel Hill Children's Hospital, Chapel Hill (T.C.W., S.P.S.); the Department of Pediatrics, Section of Critical Care Medicine, University of Colorado School of Medicine and Children's Hospital Colorado, Aurora (A.B.M.); the Division of Pediatric Critical Care Medicine, Medical University of South Carolina, Charleston (E.H.M.); the Department of Pediatrics, Division of Cardiology, Louisiana State University Health Sciences Center and Children's Hospital of New Orleans, New Orleans (T.T.B.); the Division of Pediatric Infectious Diseases, Department of Pediatrics, Children's Mercy Kansas City, Kansas City, MO (J.E.S.); the Division of Critical Care Medicine, Department of Pediatrics, Akron Children's Hospital, Akron (R.A.N.), the Department of Pediatrics, University of Cincinnati College of Medicine, Cincinnati Children's Hospital Medical Center, Cincinnati (M.A.S.), and the Division of Pediatric Critical Care Medicine, Nationwide Children's Hospital Columbus, Columbus (K.E.B.) - all in Ohio; the Division of Critical Care Medicine, Department of Anesthesiology and Critical Care, Children's Hospital of Philadelphia, Philadelphia (K.C.); the Division of Pediatric Critical Care, Department of Pediatrics, Children's Hospital and Medical Center, Omaha, NE (M.L.C.); the Division of Pediatric Critical Care, Department of Pediatrics, Saint Barnabas Medical Center, Livingston, NJ (S.J.G.); the Divisions of Pediatric Infectious Diseases and Pediatric Critical Care Medicine, Department of Pediatric and Adolescent Medicine, Mayo Clinic, Rochester (E.R.L.), and the Division of Pediatric Critical Care, University of Minnesota Masonic Children's Hospital, Minneapolis (J.R.H.) - both in Minnesota; the Division of Pediatric Critical Care Medicine, Department of Pediatrics, University of Alabama at Birmingham, Birmingham (M.K.), the Division of Pediatric Infectious Diseases, Department of Pediatrics, UHealth/Holtz Children's Hospital, Miami (B.M.C.); the Ryan White Center for Pediatric Infectious Disease and Global Health, Department of Pediatrics, Indiana University School of Medicine, Indianapolis (S.S.B.); University of Arizona, Diamond Children's Banner Children's Medical Center, Tucson (M.G.G.); the Department of Pediatrics, Department of Microbiology, Division of Infectious Diseases, University of Mississippi Medical Center, Jackson (C.V.H.); the Department of Pediatrics, Children's Hospital of Michigan, Central Michigan University, Detroit (S.M.H.), and the Division of Pediatric Critical Care Medicine, Department of Pediatrics, Mott Children's Hospital and University of Michigan, Ann Arbor (H.R.F.); and the Division of Critical Care Medicine, Department of Pediatrics, Northwestern University Feinberg School of Medicine, Ann and Robert H. Lurie Children's Hospital of Chicago, Chicago (K.N.M.).; Walker TC; From the Covid-19 Response Team, Centers for Disease Control and Prevention (S.M.O., A.M.P., L.D.Z., A.P.C., M.M.P.), and the Center for Childhood Infections and Vaccines of Children's Healthcare of Atlanta and the Department of Pediatrics, Emory University School of Medicine (S.K.) - both in Atlanta; the Department of Anesthesiology, Critical Care, and Pain Medicine, Boston Children's Hospital (M.M.N., A.G.R.), and the Departments of Anaesthesia and Pediatrics, Harvard Medical School (A.G.R.) - both in Boston; the Division of Pediatric Infectious Diseases, Department of Pediatrics, Vanderbilt University Medical Center, Nashville (N.B.H.); the Department of Pediatrics, Baylor College of Medicine, Immunization Project, Texas Children's Hospital, Houston (J.A.B., L.C.S.), and the Department of Pediatrics, Division of Critical Care Medicine, University of Texas Southwestern, Children's Medical Center Dallas, Dallas (M.M.); the Division of Infectious Diseases, Children's Hospital Los Angeles and Departments of Pediatrics and Molecular Microbiology and Immunology, University of Southern California, Los Angeles (P.S.P.), the Division of Pediatric Hospital Medicine, UC San Diego-Rady Children's Hospital, San Diego (M.A.C.), the Division of Critical Care Medicine, UCSF Benioff Children's Hospital Oakland (N.Z.C.), and the Department of Pediatrics, Divisions of Critical Care Medicine and Allergy, Immunology, and Bone Marrow Transplant, University of California, San Francisco, San Francisco (M.S.Z.) - all in California; Section of Pediatric Critical Care, Department of Pediatrics, Arkansas Children's Hospital, Little Rock (K.I.); the Department of Pediatrics, University of North Carolina at Chapel Hill Children's Hospital, Chapel Hill (T.C.W., S.P.S.); the Department of Pediatrics, Section of Critical Care Medicine, University of Colorado School of Medicine and Children's Hospital Colorado, Aurora (A.B.M.); the Division of Pediatric Critical Care Medicine, Medical University of South Carolina, Charleston (E.H.M.); the Department of Pediatrics, Division of Cardiology, Louisiana State University Health Sciences Center and Children's Hospital of New Orleans, New Orleans (T.T.B.); the Division of Pediatric Infectious Diseases, Department of Pediatrics, Children's Mercy Kansas City, Kansas City, MO (J.E.S.); the Division of Critical Care Medicine, Department of Pediatrics, Akron Children's Hospital, Akron (R.A.N.), the Department of Pediatrics, University of Cincinnati College of Medicine, Cincinnati Children's Hospital Medical Center, Cincinnati (M.A.S.), and the Division of Pediatric Critical Care Medicine, Nationwide Children's Hospital Columbus, Columbus (K.E.B.) - all in Ohio; the Division of Critical Care Medicine, Department of Anesthesiology and Critical Care, Children's Hospital of Philadelphia, Philadelphia (K.C.); the Division of Pediatric Critical Care, Department of Pediatrics, Children's Hospital and Medical Center, Omaha, NE (M.L.C.); the Division of Pediatric Critical Care, Department of Pediatrics, Saint Barnabas Medical Center, Livingston, NJ (S.J.G.); the Divisions of Pediatric Infectious Diseases and Pediatric Critical Care Medicine, Department of Pediatric and Adolescent Medicine, Mayo Clinic, Rochester (E.R.L.), and the Division of Pediatric Critical Care, University of Minnesota Masonic Children's Hospital, Minneapolis (J.R.H.) - both in Minnesota; the Division of Pediatric Critical Care Medicine, Department of Pediatrics, University of Alabama at Birmingham, Birmingham (M.K.), the Division of Pediatric Infectious Diseases, Department of Pediatrics, UHealth/Holtz Children's Hospital, Miami (B.M.C.); the Ryan White Center for Pediatric Infectious Disease and Global Health, Department of Pediatrics, Indiana University School of Medicine, Indianapolis (S.S.B.); University of Arizona, Diamond Children's Banner Children's Medical Center, Tucson (M.G.G.); the Department of Pediatrics, Department of Microbiology, Division of Infectious Diseases, University of Mississippi Medical Center, Jackson (C.V.H.); the Department of Pediatrics, Children's Hospital of Michigan, Central Michigan University, Detroit (S.M.H.), and the Division of Pediatric Critical Care Medicine, Department of Pediatrics, Mott Children's Hospital and University of Michigan, Ann Arbor (H.R.F.); and the Division of Critical Care Medicine, Department of Pediatrics, Northwestern University Feinberg School of Medicine, Ann and Robert H. Lurie Children's Hospital of Chicago, Chicago (K.N.M.).; Schwartz SP; From the Covid-19 Response Team, Centers for Disease Control and Prevention (S.M.O., A.M.P., L.D.Z., A.P.C., M.M.P.), and the Center for Childhood Infections and Vaccines of Children's Healthcare of Atlanta and the Department of Pediatrics, Emory University School of Medicine (S.K.) - both in Atlanta; the Department of Anesthesiology, Critical Care, and Pain Medicine, Boston Children's Hospital (M.M.N., A.G.R.), and the Departments of Anaesthesia and Pediatrics, Harvard Medical School (A.G.R.) - both in Boston; the Division of Pediatric Infectious Diseases, Department of Pediatrics, Vanderbilt University Medical Center, Nashville (N.B.H.); the Department of Pediatrics, Baylor College of Medicine, Immunization Project, Texas Children's Hospital, Houston (J.A.B., L.C.S.), and the Department of Pediatrics, Division of Critical Care Medicine, University of Texas Southwestern, Children's Medical Center Dallas, Dallas (M.M.); the Division of Infectious Diseases, Children's Hospital Los Angeles and Departments of Pediatrics and Molecular Microbiology and Immunology, University of Southern California, Los Angeles (P.S.P.), the Division of Pediatric Hospital Medicine, UC San Diego-Rady Children's Hospital, San Diego (M.A.C.), the Division of Critical Care Medicine, UCSF Benioff Children's Hospital Oakland (N.Z.C.), and the Department of Pediatrics, Divisions of Critical Care Medicine and Allergy, Immunology, and Bone Marrow Transplant, University of California, San Francisco, San Francisco (M.S.Z.) - all in California; Section of Pediatric Critical Care, Department of Pediatrics, Arkansas Children's Hospital, Little Rock (K.I.); the Department of Pediatrics, University of North Carolina at Chapel Hill Children's Hospital, Chapel Hill (T.C.W., S.P.S.); the Department of Pediatrics, Section of Critical Care Medicine, University of Colorado School of Medicine and Children's Hospital Colorado, Aurora (A.B.M.); the Division of Pediatric Critical Care Medicine, Medical University of South Carolina, Charleston (E.H.M.); the Department of Pediatrics, Division of Cardiology, Louisiana State University Health Sciences Center and Children's Hospital of New Orleans, New Orleans (T.T.B.); the Division of Pediatric Infectious Diseases, Department of Pediatrics, Children's Mercy Kansas City, Kansas City, MO (J.E.S.); the Division of Critical Care Medicine, Department of Pediatrics, Akron Children's Hospital, Akron (R.A.N.), the Department of Pediatrics, University of Cincinnati College of Medicine, Cincinnati Children's Hospital Medical Center, Cincinnati (M.A.S.), and the Division of Pediatric Critical Care Medicine, Nationwide Children's Hospital Columbus, Columbus (K.E.B.) - all in Ohio; the Division of Critical Care Medicine, Department of Anesthesiology and Critical Care, Children's Hospital of Philadelphia, Philadelphia (K.C.); the Division of Pediatric Critical Care, Department of Pediatrics, Children's Hospital and Medical Center, Omaha, NE (M.L.C.); the Division of Pediatric Critical Care, Department of Pediatrics, Saint Barnabas Medical Center, Livingston, NJ (S.J.G.); the Divisions of Pediatric Infectious Diseases and Pediatric Critical Care Medicine, Department of Pediatric and Adolescent Medicine, Mayo Clinic, Rochester (E.R.L.), and the Division of Pediatric Critical Care, University of Minnesota Masonic Children's Hospital, Minneapolis (J.R.H.) - both in Minnesota; the Division of Pediatric Critical Care Medicine, Department of Pediatrics, University of Alabama at Birmingham, Birmingham (M.K.), the Division of Pediatric Infectious Diseases, Department of Pediatrics, UHealth/Holtz Children's Hospital, Miami (B.M.C.); the Ryan White Center for Pediatric Infectious Disease and Global Health, Department of Pediatrics, Indiana University School of Medicine, Indianapolis (S.S.B.); University of Arizona, Diamond Children's Banner Children's Medical Center, Tucson (M.G.G.); the Department of Pediatrics, Department of Microbiology, Division of Infectious Diseases, University of Mississippi Medical Center, Jackson (C.V.H.); the Department of Pediatrics, Children's Hospital of Michigan, Central Michigan University, Detroit (S.M.H.), and the Division of Pediatric Critical Care Medicine, Department of Pediatrics, Mott Children's Hospital and University of Michigan, Ann Arbor (H.R.F.); and the Division of Critical Care Medicine, Department of Pediatrics, Northwestern University Feinberg School of Medicine, Ann and Robert H. Lurie Children's Hospital of Chicago, Chicago (K.N.M.).; Maddux AB; From the Covid-19 Response Team, Centers for Disease Control and Prevention (S.M.O., A.M.P., L.D.Z., A.P.C., M.M.P.), and the Center for Childhood Infections and Vaccines of Children's Healthcare of Atlanta and the Department of Pediatrics, Emory University School of Medicine (S.K.) - both in Atlanta; the Department of Anesthesiology, Critical Care, and Pain Medicine, Boston Children's Hospital (M.M.N., A.G.R.), and the Departments of Anaesthesia and Pediatrics, Harvard Medical School (A.G.R.) - both in Boston; the Division of Pediatric Infectious Diseases, Department of Pediatrics, Vanderbilt University Medical Center, Nashville (N.B.H.); the Department of Pediatrics, Baylor College of Medicine, Immunization Project, Texas Children's Hospital, Houston (J.A.B., L.C.S.), and the Department of Pediatrics, Division of Critical Care Medicine, University of Texas Southwestern, Children's Medical Center Dallas, Dallas (M.M.); the Division of Infectious Diseases, Children's Hospital Los Angeles and Departments of Pediatrics and Molecular Microbiology and Immunology, University of Southern California, Los Angeles (P.S.P.), the Division of Pediatric Hospital Medicine, UC San Diego-Rady Children's Hospital, San Diego (M.A.C.), the Division of Critical Care Medicine, UCSF Benioff Children's Hospital Oakland (N.Z.C.), and the Department of Pediatrics, Divisions of Critical Care Medicine and Allergy, Immunology, and Bone Marrow Transplant, University of California, San Francisco, San Francisco (M.S.Z.) - all in California; Section of Pediatric Critical Care, Department of Pediatrics, Arkansas Children's Hospital, Little Rock (K.I.); the Department of Pediatrics, University of North Carolina at Chapel Hill Children's Hospital, Chapel Hill (T.C.W., S.P.S.); the Department of Pediatrics, Section of Critical Care Medicine, University of Colorado School of Medicine and Children's Hospital Colorado, Aurora (A.B.M.); the Division of Pediatric Critical Care Medicine, Medical University of South Carolina, Charleston (E.H.M.); the Department of Pediatrics, Division of Cardiology, Louisiana State University Health Sciences Center and Children's Hospital of New Orleans, New Orleans (T.T.B.); the Division of Pediatric Infectious Diseases, Department of Pediatrics, Children's Mercy Kansas City, Kansas City, MO (J.E.S.); the Division of Critical Care Medicine, Department of Pediatrics, Akron Children's Hospital, Akron (R.A.N.), the Department of Pediatrics, University of Cincinnati College of Medicine, Cincinnati Children's Hospital Medical Center, Cincinnati (M.A.S.), and the Division of Pediatric Critical Care Medicine, Nationwide Children's Hospital Columbus, Columbus (K.E.B.) - all in Ohio; the Division of Critical Care Medicine, Department of Anesthesiology and Critical Care, Children's Hospital of Philadelphia, Philadelphia (K.C.); the Division of Pediatric Critical Care, Department of Pediatrics, Children's Hospital and Medical Center, Omaha, NE (M.L.C.); the Division of Pediatric Critical Care, Department of Pediatrics, Saint Barnabas Medical Center, Livingston, NJ (S.J.G.); the Divisions of Pediatric Infectious Diseases and Pediatric Critical Care Medicine, Department of Pediatric and Adolescent Medicine, Mayo Clinic, Rochester (E.R.L.), and the Division of Pediatric Critical Care, University of Minnesota Masonic Children's Hospital, Minneapolis (J.R.H.) - both in Minnesota; the Division of Pediatric Critical Care Medicine, Department of Pediatrics, University of Alabama at Birmingham, Birmingham (M.K.), the Division of Pediatric Infectious Diseases, Department of Pediatrics, UHealth/Holtz Children's Hospital, Miami (B.M.C.); the Ryan White Center for Pediatric Infectious Disease and Global Health, Department of Pediatrics, Indiana University School of Medicine, Indianapolis (S.S.B.); University of Arizona, Diamond Children's Banner Children's Medical Center, Tucson (M.G.G.); the Department of Pediatrics, Department of Microbiology, Division of Infectious Diseases, University of Mississippi Medical Center, Jackson (C.V.H.); the Department of Pediatrics, Children's Hospital of Michigan, Central Michigan University, Detroit (S.M.H.), and the Division of Pediatric Critical Care Medicine, Department of Pediatrics, Mott Children's Hospital and University of Michigan, Ann Arbor (H.R.F.); and the Division of Critical Care Medicine, Department of Pediatrics, Northwestern University Feinberg School of Medicine, Ann and Robert H. Lurie Children's Hospital of Chicago, Chicago (K.N.M.).; Mack EH; From the Covid-19 Response Team, Centers for Disease Control and Prevention (S.M.O., A.M.P., L.D.Z., A.P.C., M.M.P.), and the Center for Childhood Infections and Vaccines of Children's Healthcare of Atlanta and the Department of Pediatrics, Emory University School of Medicine (S.K.) - both in Atlanta; the Department of Anesthesiology, Critical Care, and Pain Medicine, Boston Children's Hospital (M.M.N., A.G.R.), and the Departments of Anaesthesia and Pediatrics, Harvard Medical School (A.G.R.) - both in Boston; the Division of Pediatric Infectious Diseases, Department of Pediatrics, Vanderbilt University Medical Center, Nashville (N.B.H.); the Department of Pediatrics, Baylor College of Medicine, Immunization Project, Texas Children's Hospital, Houston (J.A.B., L.C.S.), and the Department of Pediatrics, Division of Critical Care Medicine, University of Texas Southwestern, Children's Medical Center Dallas, Dallas (M.M.); the Division of Infectious Diseases, Children's Hospital Los Angeles and Departments of Pediatrics and Molecular Microbiology and Immunology, University of Southern California, Los Angeles (P.S.P.), the Division of Pediatric Hospital Medicine, UC San Diego-Rady Children's Hospital, San Diego (M.A.C.), the Division of Critical Care Medicine, UCSF Benioff Children's Hospital Oakland (N.Z.C.), and the Department of Pediatrics, Divisions of Critical Care Medicine and Allergy, Immunology, and Bone Marrow Transplant, University of California, San Francisco, San Francisco (M.S.Z.) - all in California; Section of Pediatric Critical Care, Department of Pediatrics, Arkansas Children's Hospital, Little Rock (K.I.); the Department of Pediatrics, University of North Carolina at Chapel Hill Children's Hospital, Chapel Hill (T.C.W., S.P.S.); the Department of Pediatrics, Section of Critical Care Medicine, University of Colorado School of Medicine and Children's Hospital Colorado, Aurora (A.B.M.); the Division of Pediatric Critical Care Medicine, Medical University of South Carolina, Charleston (E.H.M.); the Department of Pediatrics, Division of Cardiology, Louisiana State University Health Sciences Center and Children's Hospital of New Orleans, New Orleans (T.T.B.); the Division of Pediatric Infectious Diseases, Department of Pediatrics, Children's Mercy Kansas City, Kansas City, MO (J.E.S.); the Division of Critical Care Medicine, Department of Pediatrics, Akron Children's Hospital, Akron (R.A.N.), the Department of Pediatrics, University of Cincinnati College of Medicine, Cincinnati Children's Hospital Medical Center, Cincinnati (M.A.S.), and the Division of Pediatric Critical Care Medicine, Nationwide Children's Hospital Columbus, Columbus (K.E.B.) - all in Ohio; the Division of Critical Care Medicine, Department of Anesthesiology and Critical Care, Children's Hospital of Philadelphia, Philadelphia (K.C.); the Division of Pediatric Critical Care, Department of Pediatrics, Children's Hospital and Medical Center, Omaha, NE (M.L.C.); the Division of Pediatric Critical Care, Department of Pediatrics, Saint Barnabas Medical Center, Livingston, NJ (S.J.G.); the Divisions of Pediatric Infectious Diseases and Pediatric Critical Care Medicine, Department of Pediatric and Adolescent Medicine, Mayo Clinic, Rochester (E.R.L.), and the Division of Pediatric Critical Care, University of Minnesota Masonic Children's Hospital, Minneapolis (J.R.H.) - both in Minnesota; the Division of Pediatric Critical Care Medicine, Department of Pediatrics, University of Alabama at Birmingham, Birmingham (M.K.), the Division of Pediatric Infectious Diseases, Department of Pediatrics, UHealth/Holtz Children's Hospital, Miami (B.M.C.); the Ryan White Center for Pediatric Infectious Disease and Global Health, Department of Pediatrics, Indiana University School of Medicine, Indianapolis (S.S.B.); University of Arizona, Diamond Children's Banner Children's Medical Center, Tucson (M.G.G.); the Department of Pediatrics, Department of Microbiology, Division of Infectious Diseases, University of Mississippi Medical Center, Jackson (C.V.H.); the Department of Pediatrics, Children's Hospital of Michigan, Central Michigan University, Detroit (S.M.H.), and the Division of Pediatric Critical Care Medicine, Department of Pediatrics, Mott Children's Hospital and University of Michigan, Ann Arbor (H.R.F.); and the Division of Critical Care Medicine, Department of Pediatrics, Northwestern University Feinberg School of Medicine, Ann and Robert H. Lurie Children's Hospital of Chicago, Chicago (K.N.M.).; Bradford TT; From the Covid-19 Response Team, Centers for Disease Control and Prevention (S.M.O., A.M.P., L.D.Z., A.P.C., M.M.P.), and the Center for Childhood Infections and Vaccines of Children's Healthcare of Atlanta and the Department of Pediatrics, Emory University School of Medicine (S.K.) - both in Atlanta; the Department of Anesthesiology, Critical Care, and Pain Medicine, Boston Children's Hospital (M.M.N., A.G.R.), and the Departments of Anaesthesia and Pediatrics, Harvard Medical School (A.G.R.) - both in Boston; the Division of Pediatric Infectious Diseases, Department of Pediatrics, Vanderbilt University Medical Center, Nashville (N.B.H.); the Department of Pediatrics, Baylor College of Medicine, Immunization Project, Texas Children's Hospital, Houston (J.A.B., L.C.S.), and the Department of Pediatrics, Division of Critical Care Medicine, University of Texas Southwestern, Children's Medical Center Dallas, Dallas (M.M.); the Division of Infectious Diseases, Children's Hospital Los Angeles and Departments of Pediatrics and Molecular Microbiology and Immunology, University of Southern California, Los Angeles (P.S.P.), the Division of Pediatric Hospital Medicine, UC San Diego-Rady Children's Hospital, San Diego (M.A.C.), the Division of Critical Care Medicine, UCSF Benioff Children's Hospital Oakland (N.Z.C.), and the Department of Pediatrics, Divisions of Critical Care Medicine and Allergy, Immunology, and Bone Marrow Transplant, University of California, San Francisco, San Francisco (M.S.Z.) - all in California; Section of Pediatric Critical Care, Department of Pediatrics, Arkansas Children's Hospital, Little Rock (K.I.); the Department of Pediatrics, University of North Carolina at Chapel Hill Children's Hospital, Chapel Hill (T.C.W., S.P.S.); the Department of Pediatrics, Section of Critical Care Medicine, University of Colorado School of Medicine and Children's Hospital Colorado, Aurora (A.B.M.); the Division of Pediatric Critical Care Medicine, Medical University of South Carolina, Charleston (E.H.M.); the Department of Pediatrics, Division of Cardiology, Louisiana State University Health Sciences Center and Children's Hospital of New Orleans, New Orleans (T.T.B.); the Division of Pediatric Infectious Diseases, Department of Pediatrics, Children's Mercy Kansas City, Kansas City, MO (J.E.S.); the Division of Critical Care Medicine, Department of Pediatrics, Akron Children's Hospital, Akron (R.A.N.), the Department of Pediatrics, University of Cincinnati College of Medicine, Cincinnati Children's Hospital Medical Center, Cincinnati (M.A.S.), and the Division of Pediatric Critical Care Medicine, Nationwide Children's Hospital Columbus, Columbus (K.E.B.) - all in Ohio; the Division of Critical Care Medicine, Department of Anesthesiology and Critical Care, Children's Hospital of Philadelphia, Philadelphia (K.C.); the Division of Pediatric Critical Care, Department of Pediatrics, Children's Hospital and Medical Center, Omaha, NE (M.L.C.); the Division of Pediatric Critical Care, Department of Pediatrics, Saint Barnabas Medical Center, Livingston, NJ (S.J.G.); the Divisions of Pediatric Infectious Diseases and Pediatric Critical Care Medicine, Department of Pediatric and Adolescent Medicine, Mayo Clinic, Rochester (E.R.L.), and the Division of Pediatric Critical Care, University of Minnesota Masonic Children's Hospital, Minneapolis (J.R.H.) - both in Minnesota; the Division of Pediatric Critical Care Medicine, Department of Pediatrics, University of Alabama at Birmingham, Birmingham (M.K.), the Division of Pediatric Infectious Diseases, Department of Pediatrics, UHealth/Holtz Children's Hospital, Miami (B.M.C.); the Ryan White Center for Pediatric Infectious Disease and Global Health, Department of Pediatrics, Indiana University School of Medicine, Indianapolis (S.S.B.); University of Arizona, Diamond Children's Banner Children's Medical Center, Tucson (M.G.G.); the Department of Pediatrics, Department of Microbiology, Division of Infectious Diseases, University of Mississippi Medical Center, Jackson (C.V.H.); the Department of Pediatrics, Children's Hospital of Michigan, Central Michigan University, Detroit (S.M.H.), and the Division of Pediatric Critical Care Medicine, Department of Pediatrics, Mott Children's Hospital and University of Michigan, Ann Arbor (H.R.F.); and the Division of Critical Care Medicine, Department of Pediatrics, Northwestern University Feinberg School of Medicine, Ann and Robert H. Lurie Children's Hospital of Chicago, Chicago (K.N.M.).; Schuster JE; From the Covid-19 Response Team, Centers for Disease Control and Prevention (S.M.O., A.M.P., L.D.Z., A.P.C., M.M.P.), and the Center for Childhood Infections and Vaccines of Children's Healthcare of Atlanta and the Department of Pediatrics, Emory University School of Medicine (S.K.) - both in Atlanta; the Department of Anesthesiology, Critical Care, and Pain Medicine, Boston Children's Hospital (M.M.N., A.G.R.), and the Departments of Anaesthesia and Pediatrics, Harvard Medical School (A.G.R.) - both in Boston; the Division of Pediatric Infectious Diseases, Department of Pediatrics, Vanderbilt University Medical Center, Nashville (N.B.H.); the Department of Pediatrics, Baylor College of Medicine, Immunization Project, Texas Children's Hospital, Houston (J.A.B., L.C.S.), and the Department of Pediatrics, Division of Critical Care Medicine, University of Texas Southwestern, Children's Medical Center Dallas, Dallas (M.M.); the Division of Infectious Diseases, Children's Hospital Los Angeles and Departments of Pediatrics and Molecular Microbiology and Immunology, University of Southern California, Los Angeles (P.S.P.), the Division of Pediatric Hospital Medicine, UC San Diego-Rady Children's Hospital, San Diego (M.A.C.), the Division of Critical Care Medicine, UCSF Benioff Children's Hospital Oakland (N.Z.C.), and the Department of Pediatrics, Divisions of Critical Care Medicine and Allergy, Immunology, and Bone Marrow Transplant, University of California, San Francisco, San Francisco (M.S.Z.) - all in California; Section of Pediatric Critical Care, Department of Pediatrics, Arkansas Children's Hospital, Little Rock (K.I.); the Department of Pediatrics, University of North Carolina at Chapel Hill Children's Hospital, Chapel Hill (T.C.W., S.P.S.); the Department of Pediatrics, Section of Critical Care Medicine, University of Colorado School of Medicine and Children's Hospital Colorado, Aurora (A.B.M.); the Division of Pediatric Critical Care Medicine, Medical University of South Carolina, Charleston (E.H.M.); the Department of Pediatrics, Division of Cardiology, Louisiana State University Health Sciences Center and Children's Hospital of New Orleans, New Orleans (T.T.B.); the Division of Pediatric Infectious Diseases, Department of Pediatrics, Children's Mercy Kansas City, Kansas City, MO (J.E.S.); the Division of Critical Care Medicine, Department of Pediatrics, Akron Children's Hospital, Akron (R.A.N.), the Department of Pediatrics, University of Cincinnati College of Medicine, Cincinnati Children's Hospital Medical Center, Cincinnati (M.A.S.), and the Division of Pediatric Critical Care Medicine, Nationwide Children's Hospital Columbus, Columbus (K.E.B.) - all in Ohio; the Division of Critical Care Medicine, Department of Anesthesiology and Critical Care, Children's Hospital of Philadelphia, Philadelphia (K.C.); the Division of Pediatric Critical Care, Department of Pediatrics, Children's Hospital and Medical Center, Omaha, NE (M.L.C.); the Division of Pediatric Critical Care, Department of Pediatrics, Saint Barnabas Medical Center, Livingston, NJ (S.J.G.); the Divisions of Pediatric Infectious Diseases and Pediatric Critical Care Medicine, Department of Pediatric and Adolescent Medicine, Mayo Clinic, Rochester (E.R.L.), and the Division of Pediatric Critical Care, University of Minnesota Masonic Children's Hospital, Minneapolis (J.R.H.) - both in Minnesota; the Division of Pediatric Critical Care Medicine, Department of Pediatrics, University of Alabama at Birmingham, Birmingham (M.K.), the Division of Pediatric Infectious Diseases, Department of Pediatrics, UHealth/Holtz Children's Hospital, Miami (B.M.C.); the Ryan White Center for Pediatric Infectious Disease and Global Health, Department of Pediatrics, Indiana University School of Medicine, Indianapolis (S.S.B.); University of Arizona, Diamond Children's Banner Children's Medical Center, Tucson (M.G.G.); the Department of Pediatrics, Department of Microbiology, Division of Infectious Diseases, University of Mississippi Medical Center, Jackson (C.V.H.); the Department of Pediatrics, Children's Hospital of Michigan, Central Michigan University, Detroit (S.M.H.), and the Division of Pediatric Critical Care Medicine, Department of Pediatrics, Mott Children's Hospital and University of Michigan, Ann Arbor (H.R.F.); and the Division of Critical Care Medicine, Department of Pediatrics, Northwestern University Feinberg School of Medicine, Ann and Robert H. Lurie Children's Hospital of Chicago, Chicago (K.N.M.).; Nofziger RA; From the Covid-19 Response Team, Centers for Disease Control and Prevention (S.M.O., A.M.P., L.D.Z., A.P.C., M.M.P.), and the Center for Childhood Infections and Vaccines of Children's Healthcare of Atlanta and the Department of Pediatrics, Emory University School of Medicine (S.K.) - both in Atlanta; the Department of Anesthesiology, Critical Care, and Pain Medicine, Boston Children's Hospital (M.M.N., A.G.R.), and the Departments of Anaesthesia and Pediatrics, Harvard Medical School (A.G.R.) - both in Boston; the Division of Pediatric Infectious Diseases, Department of Pediatrics, Vanderbilt University Medical Center, Nashville (N.B.H.); the Department of Pediatrics, Baylor College of Medicine, Immunization Project, Texas Children's Hospital, Houston (J.A.B., L.C.S.), and the Department of Pediatrics, Division of Critical Care Medicine, University of Texas Southwestern, Children's Medical Center Dallas, Dallas (M.M.); the Division of Infectious Diseases, Children's Hospital Los Angeles and Departments of Pediatrics and Molecular Microbiology and Immunology, University of Southern California, Los Angeles (P.S.P.), the Division of Pediatric Hospital Medicine, UC San Diego-Rady Children's Hospital, San Diego (M.A.C.), the Division of Critical Care Medicine, UCSF Benioff Children's Hospital Oakland (N.Z.C.), and the Department of Pediatrics, Divisions of Critical Care Medicine and Allergy, Immunology, and Bone Marrow Transplant, University of California, San Francisco, San Francisco (M.S.Z.) - all in California; Section of Pediatric Critical Care, Department of Pediatrics, Arkansas Children's Hospital, Little Rock (K.I.); the Department of Pediatrics, University of North Carolina at Chapel Hill Children's Hospital, Chapel Hill (T.C.W., S.P.S.); the Department of Pediatrics, Section of Critical Care Medicine, University of Colorado School of Medicine and Children's Hospital Colorado, Aurora (A.B.M.); the Division of Pediatric Critical Care Medicine, Medical University of South Carolina, Charleston (E.H.M.); the Department of Pediatrics, Division of Cardiology, Louisiana State University Health Sciences Center and Children's Hospital of New Orleans, New Orleans (T.T.B.); the Division of Pediatric Infectious Diseases, Department of Pediatrics, Children's Mercy Kansas City, Kansas City, MO (J.E.S.); the Division of Critical Care Medicine, Department of Pediatrics, Akron Children's Hospital, Akron (R.A.N.), the Department of Pediatrics, University of Cincinnati College of Medicine, Cincinnati Children's Hospital Medical Center, Cincinnati (M.A.S.), and the Division of Pediatric Critical Care Medicine, Nationwide Children's Hospital Columbus, Columbus (K.E.B.) - all in Ohio; the Division of Critical Care Medicine, Department of Anesthesiology and Critical Care, Children's Hospital of Philadelphia, Philadelphia (K.C.); the Division of Pediatric Critical Care, Department of Pediatrics, Children's Hospital and Medical Center, Omaha, NE (M.L.C.); the Division of Pediatric Critical Care, Department of Pediatrics, Saint Barnabas Medical Center, Livingston, NJ (S.J.G.); the Divisions of Pediatric Infectious Diseases and Pediatric Critical Care Medicine, Department of Pediatric and Adolescent Medicine, Mayo Clinic, Rochester (E.R.L.), and the Division of Pediatric Critical Care, University of Minnesota Masonic Children's Hospital, Minneapolis (J.R.H.) - both in Minnesota; the Division of Pediatric Critical Care Medicine, Department of Pediatrics, University of Alabama at Birmingham, Birmingham (M.K.), the Division of Pediatric Infectious Diseases, Department of Pediatrics, UHealth/Holtz Children's Hospital, Miami (B.M.C.); the Ryan White Center for Pediatric Infectious Disease and Global Health, Department of Pediatrics, Indiana University School of Medicine, Indianapolis (S.S.B.); University of Arizona, Diamond Children's Banner Children's Medical Center, Tucson (M.G.G.); the Department of Pediatrics, Department of Microbiology, Division of Infectious Diseases, University of Mississippi Medical Center, Jackson (C.V.H.); the Department of Pediatrics, Children's Hospital of Michigan, Central Michigan University, Detroit (S.M.H.), and the Division of Pediatric Critical Care Medicine, Department of Pediatrics, Mott Children's Hospital and University of Michigan, Ann Arbor (H.R.F.); and the Division of Critical Care Medicine, Department of Pediatrics, Northwestern University Feinberg School of Medicine, Ann and Robert H. Lurie Children's Hospital of Chicago, Chicago (K.N.M.).; Cameron MA; From the Covid-19 Response Team, Centers for Disease Control and Prevention (S.M.O., A.M.P., L.D.Z., A.P.C., M.M.P.), and the Center for Childhood Infections and Vaccines of Children's Healthcare of Atlanta and the Department of Pediatrics, Emory University School of Medicine (S.K.) - both in Atlanta; the Department of Anesthesiology, Critical Care, and Pain Medicine, Boston Children's Hospital (M.M.N., A.G.R.), and the Departments of Anaesthesia and Pediatrics, Harvard Medical School (A.G.R.) - both in Boston; the Division of Pediatric Infectious Diseases, Department of Pediatrics, Vanderbilt University Medical Center, Nashville (N.B.H.); the Department of Pediatrics, Baylor College of Medicine, Immunization Project, Texas Children's Hospital, Houston (J.A.B., L.C.S.), and the Department of Pediatrics, Division of Critical Care Medicine, University of Texas Southwestern, Children's Medical Center Dallas, Dallas (M.M.); the Division of Infectious Diseases, Children's Hospital Los Angeles and Departments of Pediatrics and Molecular Microbiology and Immunology, University of Southern California, Los Angeles (P.S.P.), the Division of Pediatric Hospital Medicine, UC San Diego-Rady Children's Hospital, San Diego (M.A.C.), the Division of Critical Care Medicine, UCSF Benioff Children's Hospital Oakland (N.Z.C.), and the Department of Pediatrics, Divisions of Critical Care Medicine and Allergy, Immunology, and Bone Marrow Transplant, University of California, San Francisco, San Francisco (M.S.Z.) - all in California; Section of Pediatric Critical Care, Department of Pediatrics, Arkansas Children's Hospital, Little Rock (K.I.); the Department of Pediatrics, University of North Carolina at Chapel Hill Children's Hospital, Chapel Hill (T.C.W., S.P.S.); the Department of Pediatrics, Section of Critical Care Medicine, University of Colorado School of Medicine and Children's Hospital Colorado, Aurora (A.B.M.); the Division of Pediatric Critical Care Medicine, Medical University of South Carolina, Charleston (E.H.M.); the Department of Pediatrics, Division of Cardiology, Louisiana State University Health Sciences Center and Children's Hospital of New Orleans, New Orleans (T.T.B.); the Division of Pediatric Infectious Diseases, Department of Pediatrics, Children's Mercy Kansas City, Kansas City, MO (J.E.S.); the Division of Critical Care Medicine, Department of Pediatrics, Akron Children's Hospital, Akron (R.A.N.), the Department of Pediatrics, University of Cincinnati College of Medicine, Cincinnati Children's Hospital Medical Center, Cincinnati (M.A.S.), and the Division of Pediatric Critical Care Medicine, Nationwide Children's Hospital Columbus, Columbus (K.E.B.) - all in Ohio; the Division of Critical Care Medicine, Department of Anesthesiology and Critical Care, Children's Hospital of Philadelphia, Philadelphia (K.C.); the Division of Pediatric Critical Care, Department of Pediatrics, Children's Hospital and Medical Center, Omaha, NE (M.L.C.); the Division of Pediatric Critical Care, Department of Pediatrics, Saint Barnabas Medical Center, Livingston, NJ (S.J.G.); the Divisions of Pediatric Infectious Diseases and Pediatric Critical Care Medicine, Department of Pediatric and Adolescent Medicine, Mayo Clinic, Rochester (E.R.L.), and the Division of Pediatric Critical Care, University of Minnesota Masonic Children's Hospital, Minneapolis (J.R.H.) - both in Minnesota; the Division of Pediatric Critical Care Medicine, Department of Pediatrics, University of Alabama at Birmingham, Birmingham (M.K.), the Division of Pediatric Infectious Diseases, Department of Pediatrics, UHealth/Holtz Children's Hospital, Miami (B.M.C.); the Ryan White Center for Pediatric Infectious Disease and Global Health, Department of Pediatrics, Indiana University School of Medicine, Indianapolis (S.S.B.); University of Arizona, Diamond Children's Banner Children's Medical Center, Tucson (M.G.G.); the Department of Pediatrics, Department of Microbiology, Division of Infectious Diseases, University of Mississippi Medical Center, Jackson (C.V.H.); the Department of Pediatrics, Children's Hospital of Michigan, Central Michigan University, Detroit (S.M.H.), and the Division of Pediatric Critical Care Medicine, Department of Pediatrics, Mott Children's Hospital and University of Michigan, Ann Arbor (H.R.F.); and the Division of Critical Care Medicine, Department of Pediatrics, Northwestern University Feinberg School of Medicine, Ann and Robert H. Lurie Children's Hospital of Chicago, Chicago (K.N.M.).; Chiotos K; From the Covid-19 Response Team, Centers for Disease Control and Prevention (S.M.O., A.M.P., L.D.Z., A.P.C., M.M.P.), and the Center for Childhood Infections and Vaccines of Children's Healthcare of Atlanta and the Department of Pediatrics, Emory University School of Medicine (S.K.) - both in Atlanta; the Department of Anesthesiology, Critical Care, and Pain Medicine, Boston Children's Hospital (M.M.N., A.G.R.), and the Departments of Anaesthesia and Pediatrics, Harvard Medical School (A.G.R.) - both in Boston; the Division of Pediatric Infectious Diseases, Department of Pediatrics, Vanderbilt University Medical Center, Nashville (N.B.H.); the Department of Pediatrics, Baylor College of Medicine, Immunization Project, Texas Children's Hospital, Houston (J.A.B., L.C.S.), and the Department of Pediatrics, Division of Critical Care Medicine, University of Texas Southwestern, Children's Medical Center Dallas, Dallas (M.M.); the Division of Infectious Diseases, Children's Hospital Los Angeles and Departments of Pediatrics and Molecular Microbiology and Immunology, University of Southern California, Los Angeles (P.S.P.), the Division of Pediatric Hospital Medicine, UC San Diego-Rady Children's Hospital, San Diego (M.A.C.), the Division of Critical Care Medicine, UCSF Benioff Children's Hospital Oakland (N.Z.C.), and the Department of Pediatrics, Divisions of Critical Care Medicine and Allergy, Immunology, and Bone Marrow Transplant, University of California, San Francisco, San Francisco (M.S.Z.) - all in California; Section of Pediatric Critical Care, Department of Pediatrics, Arkansas Children's Hospital, Little Rock (K.I.); the Department of Pediatrics, University of North Carolina at Chapel Hill Children's Hospital, Chapel Hill (T.C.W., S.P.S.); the Department of Pediatrics, Section of Critical Care Medicine, University of Colorado School of Medicine and Children's Hospital Colorado, Aurora (A.B.M.); the Division of Pediatric Critical Care Medicine, Medical University of South Carolina, Charleston (E.H.M.); the Department of Pediatrics, Division of Cardiology, Louisiana State University Health Sciences Center and Children's Hospital of New Orleans, New Orleans (T.T.B.); the Division of Pediatric Infectious Diseases, Department of Pediatrics, Children's Mercy Kansas City, Kansas City, MO (J.E.S.); the Division of Critical Care Medicine, Department of Pediatrics, Akron Children's Hospital, Akron (R.A.N.), the Department of Pediatrics, University of Cincinnati College of Medicine, Cincinnati Children's Hospital Medical Center, Cincinnati (M.A.S.), and the Division of Pediatric Critical Care Medicine, Nationwide Children's Hospital Columbus, Columbus (K.E.B.) - all in Ohio; the Division of Critical Care Medicine, Department of Anesthesiology and Critical Care, Children's Hospital of Philadelphia, Philadelphia (K.C.); the Division of Pediatric Critical Care, Department of Pediatrics, Children's Hospital and Medical Center, Omaha, NE (M.L.C.); the Division of Pediatric Critical Care, Department of Pediatrics, Saint Barnabas Medical Center, Livingston, NJ (S.J.G.); the Divisions of Pediatric Infectious Diseases and Pediatric Critical Care Medicine, Department of Pediatric and Adolescent Medicine, Mayo Clinic, Rochester (E.R.L.), and the Division of Pediatric Critical Care, University of Minnesota Masonic Children's Hospital, Minneapolis (J.R.H.) - both in Minnesota; the Division of Pediatric Critical Care Medicine, Department of Pediatrics, University of Alabama at Birmingham, Birmingham (M.K.), the Division of Pediatric Infectious Diseases, Department of Pediatrics, UHealth/Holtz Children's Hospital, Miami (B.M.C.); the Ryan White Center for Pediatric Infectious Disease and Global Health, Department of Pediatrics, Indiana University School of Medicine, Indianapolis (S.S.B.); University of Arizona, Diamond Children's Banner Children's Medical Center, Tucson (M.G.G.); the Department of Pediatrics, Department of Microbiology, Division of Infectious Diseases, University of Mississippi Medical Center, Jackson (C.V.H.); the Department of Pediatrics, Children's Hospital of Michigan, Central Michigan University, Detroit (S.M.H.), and the Division of Pediatric Critical Care Medicine, Department of Pediatrics, Mott Children's Hospital and University of Michigan, Ann Arbor (H.R.F.); and the Division of Critical Care Medicine, Department of Pediatrics, Northwestern University Feinberg School of Medicine, Ann and Robert H. Lurie Children's Hospital of Chicago, Chicago (K.N.M.).; Cullimore ML; From the Covid-19 Response Team, Centers for Disease Control and Prevention (S.M.O., A.M.P., L.D.Z., A.P.C., M.M.P.), and the Center for Childhood Infections and Vaccines of Children's Healthcare of Atlanta and the Department of Pediatrics, Emory University School of Medicine (S.K.) - both in Atlanta; the Department of Anesthesiology, Critical Care, and Pain Medicine, Boston Children's Hospital (M.M.N., A.G.R.), and the Departments of Anaesthesia and Pediatrics, Harvard Medical School (A.G.R.) - both in Boston; the Division of Pediatric Infectious Diseases, Department of Pediatrics, Vanderbilt University Medical Center, Nashville (N.B.H.); the Department of Pediatrics, Baylor College of Medicine, Immunization Project, Texas Children's Hospital, Houston (J.A.B., L.C.S.), and the Department of Pediatrics, Division of Critical Care Medicine, University of Texas Southwestern, Children's Medical Center Dallas, Dallas (M.M.); the Division of Infectious Diseases, Children's Hospital Los Angeles and Departments of Pediatrics and Molecular Microbiology and Immunology, University of Southern California, Los Angeles (P.S.P.), the Division of Pediatric Hospital Medicine, UC San Diego-Rady Children's Hospital, San Diego (M.A.C.), the Division of Critical Care Medicine, UCSF Benioff Children's Hospital Oakland (N.Z.C.), and the Department of Pediatrics, Divisions of Critical Care Medicine and Allergy, Immunology, and Bone Marrow Transplant, University of California, San Francisco, San Francisco (M.S.Z.) - all in California; Section of Pediatric Critical Care, Department of Pediatrics, Arkansas Children's Hospital, Little Rock (K.I.); the Department of Pediatrics, University of North Carolina at Chapel Hill Children's Hospital, Chapel Hill (T.C.W., S.P.S.); the Department of Pediatrics, Section of Critical Care Medicine, University of Colorado School of Medicine and Children's Hospital Colorado, Aurora (A.B.M.); the Division of Pediatric Critical Care Medicine, Medical University of South Carolina, Charleston (E.H.M.); the Department of Pediatrics, Division of Cardiology, Louisiana State University Health Sciences Center and Children's Hospital of New Orleans, New Orleans (T.T.B.); the Division of Pediatric Infectious Diseases, Department of Pediatrics, Children's Mercy Kansas City, Kansas City, MO (J.E.S.); the Division of Critical Care Medicine, Department of Pediatrics, Akron Children's Hospital, Akron (R.A.N.), the Department of Pediatrics, University of Cincinnati College of Medicine, Cincinnati Children's Hospital Medical Center, Cincinnati (M.A.S.), and the Division of Pediatric Critical Care Medicine, Nationwide Children's Hospital Columbus, Columbus (K.E.B.) - all in Ohio; the Division of Critical Care Medicine, Department of Anesthesiology and Critical Care, Children's Hospital of Philadelphia, Philadelphia (K.C.); the Division of Pediatric Critical Care, Department of Pediatrics, Children's Hospital and Medical Center, Omaha, NE (M.L.C.); the Division of Pediatric Critical Care, Department of Pediatrics, Saint Barnabas Medical Center, Livingston, NJ (S.J.G.); the Divisions of Pediatric Infectious Diseases and Pediatric Critical Care Medicine, Department of Pediatric and Adolescent Medicine, Mayo Clinic, Rochester (E.R.L.), and the Division of Pediatric Critical Care, University of Minnesota Masonic Children's Hospital, Minneapolis (J.R.H.) - both in Minnesota; the Division of Pediatric Critical Care Medicine, Department of Pediatrics, University of Alabama at Birmingham, Birmingham (M.K.), the Division of Pediatric Infectious Diseases, Department of Pediatrics, UHealth/Holtz Children's Hospital, Miami (B.M.C.); the Ryan White Center for Pediatric Infectious Disease and Global Health, Department of Pediatrics, Indiana University School of Medicine, Indianapolis (S.S.B.); University of Arizona, Diamond Children's Banner Children's Medical Center, Tucson (M.G.G.); the Department of Pediatrics, Department of Microbiology, Division of Infectious Diseases, University of Mississippi Medical Center, Jackson (C.V.H.); the Department of Pediatrics, Children's Hospital of Michigan, Central Michigan University, Detroit (S.M.H.), and the Division of Pediatric Critical Care Medicine, Department of Pediatrics, Mott Children's Hospital and University of Michigan, Ann Arbor (H.R.F.); and the Division of Critical Care Medicine, Department of Pediatrics, Northwestern University Feinberg School of Medicine, Ann and Robert H. Lurie Children's Hospital of Chicago, Chicago (K.N.M.).; Gertz SJ; From the Covid-19 Response Team, Centers for Disease Control and Prevention (S.M.O., A.M.P., L.D.Z., A.P.C., M.M.P.), and the Center for Childhood Infections and Vaccines of Children's Healthcare of Atlanta and the Department of Pediatrics, Emory University School of Medicine (S.K.) - both in Atlanta; the Department of Anesthesiology, Critical Care, and Pain Medicine, Boston Children's Hospital (M.M.N., A.G.R.), and the Departments of Anaesthesia and Pediatrics, Harvard Medical School (A.G.R.) - both in Boston; the Division of Pediatric Infectious Diseases, Department of Pediatrics, Vanderbilt University Medical Center, Nashville (N.B.H.); the Department of Pediatrics, Baylor College of Medicine, Immunization Project, Texas Children's Hospital, Houston (J.A.B., L.C.S.), and the Department of Pediatrics, Division of Critical Care Medicine, University of Texas Southwestern, Children's Medical Center Dallas, Dallas (M.M.); the Division of Infectious Diseases, Children's Hospital Los Angeles and Departments of Pediatrics and Molecular Microbiology and Immunology, University of Southern California, Los Angeles (P.S.P.), the Division of Pediatric Hospital Medicine, UC San Diego-Rady Children's Hospital, San Diego (M.A.C.), the Division of Critical Care Medicine, UCSF Benioff Children's Hospital Oakland (N.Z.C.), and the Department of Pediatrics, Divisions of Critical Care Medicine and Allergy, Immunology, and Bone Marrow Transplant, University of California, San Francisco, San Francisco (M.S.Z.) - all in California; Section of Pediatric Critical Care, Department of Pediatrics, Arkansas Children's Hospital, Little Rock (K.I.); the Department of Pediatrics, University of North Carolina at Chapel Hill Children's Hospital, Chapel Hill (T.C.W., S.P.S.); the Department of Pediatrics, Section of Critical Care Medicine, University of Colorado School of Medicine and Children's Hospital Colorado, Aurora (A.B.M.); the Division of Pediatric Critical Care Medicine, Medical University of South Carolina, Charleston (E.H.M.); the Department of Pediatrics, Division of Cardiology, Louisiana State University Health Sciences Center and Children's Hospital of New Orleans, New Orleans (T.T.B.); the Division of Pediatric Infectious Diseases, Department of Pediatrics, Children's Mercy Kansas City, Kansas City, MO (J.E.S.); the Division of Critical Care Medicine, Department of Pediatrics, Akron Children's Hospital, Akron (R.A.N.), the Department of Pediatrics, University of Cincinnati College of Medicine, Cincinnati Children's Hospital Medical Center, Cincinnati (M.A.S.), and the Division of Pediatric Critical Care Medicine, Nationwide Children's Hospital Columbus, Columbus (K.E.B.) - all in Ohio; the Division of Critical Care Medicine, Department of Anesthesiology and Critical Care, Children's Hospital of Philadelphia, Philadelphia (K.C.); the Division of Pediatric Critical Care, Department of Pediatrics, Children's Hospital and Medical Center, Omaha, NE (M.L.C.); the Division of Pediatric Critical Care, Department of Pediatrics, Saint Barnabas Medical Center, Livingston, NJ (S.J.G.); the Divisions of Pediatric Infectious Diseases and Pediatric Critical Care Medicine, Department of Pediatric and Adolescent Medicine, Mayo Clinic, Rochester (E.R.L.), and the Division of Pediatric Critical Care, University of Minnesota Masonic Children's Hospital, Minneapolis (J.R.H.) - both in Minnesota; the Division of Pediatric Critical Care Medicine, Department of Pediatrics, University of Alabama at Birmingham, Birmingham (M.K.), the Division of Pediatric Infectious Diseases, Department of Pediatrics, UHealth/Holtz Children's Hospital, Miami (B.M.C.); the Ryan White Center for Pediatric Infectious Disease and Global Health, Department of Pediatrics, Indiana University School of Medicine, Indianapolis (S.S.B.); University of Arizona, Diamond Children's Banner Children's Medical Center, Tucson (M.G.G.); the Department of Pediatrics, Department of Microbiology, Division of Infectious Diseases, University of Mississippi Medical Center, Jackson (C.V.H.); the Department of Pediatrics, Children's Hospital of Michigan, Central Michigan University, Detroit (S.M.H.), and the Division of Pediatric Critical Care Medicine, Department of Pediatrics, Mott Children's Hospital and University of Michigan, Ann Arbor (H.R.F.); and the Division of Critical Care Medicine, Department of Pediatrics, Northwestern University Feinberg School of Medicine, Ann and Robert H. Lurie Children's Hospital of Chicago, Chicago (K.N.M.).; Levy ER; From the Covid-19 Response Team, Centers for Disease Control and Prevention (S.M.O., A.M.P., L.D.Z., A.P.C., M.M.P.), and the Center for Childhood Infections and Vaccines of Children's Healthcare of Atlanta and the Department of Pediatrics, Emory University School of Medicine (S.K.) - both in Atlanta; the Department of Anesthesiology, Critical Care, and Pain Medicine, Boston Children's Hospital (M.M.N., A.G.R.), and the Departments of Anaesthesia and Pediatrics, Harvard Medical School (A.G.R.) - both in Boston; the Division of Pediatric Infectious Diseases, Department of Pediatrics, Vanderbilt University Medical Center, Nashville (N.B.H.); the Department of Pediatrics, Baylor College of Medicine, Immunization Project, Texas Children's Hospital, Houston (J.A.B., L.C.S.), and the Department of Pediatrics, Division of Critical Care Medicine, University of Texas Southwestern, Children's Medical Center Dallas, Dallas (M.M.); the Division of Infectious Diseases, Children's Hospital Los Angeles and Departments of Pediatrics and Molecular Microbiology and Immunology, University of Southern California, Los Angeles (P.S.P.), the Division of Pediatric Hospital Medicine, UC San Diego-Rady Children's Hospital, San Diego (M.A.C.), the Division of Critical Care Medicine, UCSF Benioff Children's Hospital Oakland (N.Z.C.), and the Department of Pediatrics, Divisions of Critical Care Medicine and Allergy, Immunology, and Bone Marrow Transplant, University of California, San Francisco, San Francisco (M.S.Z.) - all in California; Section of Pediatric Critical Care, Department of Pediatrics, Arkansas Children's Hospital, Little Rock (K.I.); the Department of Pediatrics, University of North Carolina at Chapel Hill Children's Hospital, Chapel Hill (T.C.W., S.P.S.); the Department of Pediatrics, Section of Critical Care Medicine, University of Colorado School of Medicine and Children's Hospital Colorado, Aurora (A.B.M.); the Division of Pediatric Critical Care Medicine, Medical University of South Carolina, Charleston (E.H.M.); the Department of Pediatrics, Division of Cardiology, Louisiana State University Health Sciences Center and Children's Hospital of New Orleans, New Orleans (T.T.B.); the Division of Pediatric Infectious Diseases, Department of Pediatrics, Children's Mercy Kansas City, Kansas City, MO (J.E.S.); the Division of Critical Care Medicine, Department of Pediatrics, Akron Children's Hospital, Akron (R.A.N.), the Department of Pediatrics, University of Cincinnati College of Medicine, Cincinnati Children's Hospital Medical Center, Cincinnati (M.A.S.), and the Division of Pediatric Critical Care Medicine, Nationwide Children's Hospital Columbus, Columbus (K.E.B.) - all in Ohio; the Division of Critical Care Medicine, Department of Anesthesiology and Critical Care, Children's Hospital of Philadelphia, Philadelphia (K.C.); the Division of Pediatric Critical Care, Department of Pediatrics, Children's Hospital and Medical Center, Omaha, NE (M.L.C.); the Division of Pediatric Critical Care, Department of Pediatrics, Saint Barnabas Medical Center, Livingston, NJ (S.J.G.); the Divisions of Pediatric Infectious Diseases and Pediatric Critical Care Medicine, Department of Pediatric and Adolescent Medicine, Mayo Clinic, Rochester (E.R.L.), and the Division of Pediatric Critical Care, University of Minnesota Masonic Children's Hospital, Minneapolis (J.R.H.) - both in Minnesota; the Division of Pediatric Critical Care Medicine, Department of Pediatrics, University of Alabama at Birmingham, Birmingham (M.K.), the Division of Pediatric Infectious Diseases, Department of Pediatrics, UHealth/Holtz Children's Hospital, Miami (B.M.C.); the Ryan White Center for Pediatric Infectious Disease and Global Health, Department of Pediatrics, Indiana University School of Medicine, Indianapolis (S.S.B.); University of Arizona, Diamond Children's Banner Children's Medical Center, Tucson (M.G.G.); the Department of Pediatrics, Department of Microbiology, Division of Infectious Diseases, University of Mississippi Medical Center, Jackson (C.V.H.); the Department of Pediatrics, Children's Hospital of Michigan, Central Michigan University, Detroit (S.M.H.), and the Division of Pediatric Critical Care Medicine, Department of Pediatrics, Mott Children's Hospital and University of Michigan, Ann Arbor (H.R.F.); and the Division of Critical Care Medicine, Department of Pediatrics, Northwestern University Feinberg School of Medicine, Ann and Robert H. Lurie Children's Hospital of Chicago, Chicago (K.N.M.).; Kong M; From the Covid-19 Response Team, Centers for Disease Control and Prevention (S.M.O., A.M.P., L.D.Z., A.P.C., M.M.P.), and the Center for Childhood Infections and Vaccines of Children's Healthcare of Atlanta and the Department of Pediatrics, Emory University School of Medicine (S.K.) - both in Atlanta; the Department of Anesthesiology, Critical Care, and Pain Medicine, Boston Children's Hospital (M.M.N., A.G.R.), and the Departments of Anaesthesia and Pediatrics, Harvard Medical School (A.G.R.) - both in Boston; the Division of Pediatric Infectious Diseases, Department of Pediatrics, Vanderbilt University Medical Center, Nashville (N.B.H.); the Department of Pediatrics, Baylor College of Medicine, Immunization Project, Texas Children's Hospital, Houston (J.A.B., L.C.S.), and the Department of Pediatrics, Division of Critical Care Medicine, University of Texas Southwestern, Children's Medical Center Dallas, Dallas (M.M.); the Division of Infectious Diseases, Children's Hospital Los Angeles and Departments of Pediatrics and Molecular Microbiology and Immunology, University of Southern California, Los Angeles (P.S.P.), the Division of Pediatric Hospital Medicine, UC San Diego-Rady Children's Hospital, San Diego (M.A.C.), the Division of Critical Care Medicine, UCSF Benioff Children's Hospital Oakland (N.Z.C.), and the Department of Pediatrics, Divisions of Critical Care Medicine and Allergy, Immunology, and Bone Marrow Transplant, University of California, San Francisco, San Francisco (M.S.Z.) - all in California; Section of Pediatric Critical Care, Department of Pediatrics, Arkansas Children's Hospital, Little Rock (K.I.); the Department of Pediatrics, University of North Carolina at Chapel Hill Children's Hospital, Chapel Hill (T.C.W., S.P.S.); the Department of Pediatrics, Section of Critical Care Medicine, University of Colorado School of Medicine and Children's Hospital Colorado, Aurora (A.B.M.); the Division of Pediatric Critical Care Medicine, Medical University of South Carolina, Charleston (E.H.M.); the Department of Pediatrics, Division of Cardiology, Louisiana State University Health Sciences Center and Children's Hospital of New Orleans, New Orleans (T.T.B.); the Division of Pediatric Infectious Diseases, Department of Pediatrics, Children's Mercy Kansas City, Kansas City, MO (J.E.S.); the Division of Critical Care Medicine, Department of Pediatrics, Akron Children's Hospital, Akron (R.A.N.), the Department of Pediatrics, University of Cincinnati College of Medicine, Cincinnati Children's Hospital Medical Center, Cincinnati (M.A.S.), and the Division of Pediatric Critical Care Medicine, Nationwide Children's Hospital Columbus, Columbus (K.E.B.) - all in Ohio; the Division of Critical Care Medicine, Department of Anesthesiology and Critical Care, Children's Hospital of Philadelphia, Philadelphia (K.C.); the Division of Pediatric Critical Care, Department of Pediatrics, Children's Hospital and Medical Center, Omaha, NE (M.L.C.); the Division of Pediatric Critical Care, Department of Pediatrics, Saint Barnabas Medical Center, Livingston, NJ (S.J.G.); the Divisions of Pediatric Infectious Diseases and Pediatric Critical Care Medicine, Department of Pediatric and Adolescent Medicine, Mayo Clinic, Rochester (E.R.L.), and the Division of Pediatric Critical Care, University of Minnesota Masonic Children's Hospital, Minneapolis (J.R.H.) - both in Minnesota; the Division of Pediatric Critical Care Medicine, Department of Pediatrics, University of Alabama at Birmingham, Birmingham (M.K.), the Division of Pediatric Infectious Diseases, Department of Pediatrics, UHealth/Holtz Children's Hospital, Miami (B.M.C.); the Ryan White Center for Pediatric Infectious Disease and Global Health, Department of Pediatrics, Indiana University School of Medicine, Indianapolis (S.S.B.); University of Arizona, Diamond Children's Banner Children's Medical Center, Tucson (M.G.G.); the Department of Pediatrics, Department of Microbiology, Division of Infectious Diseases, University of Mississippi Medical Center, Jackson (C.V.H.); the Department of Pediatrics, Children's Hospital of Michigan, Central Michigan University, Detroit (S.M.H.), and the Division of Pediatric Critical Care Medicine, Department of Pediatrics, Mott Children's Hospital and University of Michigan, Ann Arbor (H.R.F.); and the Division of Critical Care Medicine, Department of Pediatrics, Northwestern University Feinberg School of Medicine, Ann and Robert H. Lurie Children's Hospital of Chicago, Chicago (K.N.M.).; Cvijanovich NZ; From the Covid-19 Response Team, Centers for Disease Control and Prevention (S.M.O., A.M.P., L.D.Z., A.P.C., M.M.P.), and the Center for Childhood Infections and Vaccines of Children's Healthcare of Atlanta and the Department of Pediatrics, Emory University School of Medicine (S.K.) - both in Atlanta; the Department of Anesthesiology, Critical Care, and Pain Medicine, Boston Children's Hospital (M.M.N., A.G.R.), and the Departments of Anaesthesia and Pediatrics, Harvard Medical School (A.G.R.) - both in Boston; the Division of Pediatric Infectious Diseases, Department of Pediatrics, Vanderbilt University Medical Center, Nashville (N.B.H.); the Department of Pediatrics, Baylor College of Medicine, Immunization Project, Texas Children's Hospital, Houston (J.A.B., L.C.S.), and the Department of Pediatrics, Division of Critical Care Medicine, University of Texas Southwestern, Children's Medical Center Dallas, Dallas (M.M.); the Division of Infectious Diseases, Children's Hospital Los Angeles and Departments of Pediatrics and Molecular Microbiology and Immunology, University of Southern California, Los Angeles (P.S.P.), the Division of Pediatric Hospital Medicine, UC San Diego-Rady Children's Hospital, San Diego (M.A.C.), the Division of Critical Care Medicine, UCSF Benioff Children's Hospital Oakland (N.Z.C.), and the Department of Pediatrics, Divisions of Critical Care Medicine and Allergy, Immunology, and Bone Marrow Transplant, University of California, San Francisco, San Francisco (M.S.Z.) - all in California; Section of Pediatric Critical Care, Department of Pediatrics, Arkansas Children's Hospital, Little Rock (K.I.); the Department of Pediatrics, University of North Carolina at Chapel Hill Children's Hospital, Chapel Hill (T.C.W., S.P.S.); the Department of Pediatrics, Section of Critical Care Medicine, University of Colorado School of Medicine and Children's Hospital Colorado, Aurora (A.B.M.); the Division of Pediatric Critical Care Medicine, Medical University of South Carolina, Charleston (E.H.M.); the Department of Pediatrics, Division of Cardiology, Louisiana State University Health Sciences Center and Children's Hospital of New Orleans, New Orleans (T.T.B.); the Division of Pediatric Infectious Diseases, Department of Pediatrics, Children's Mercy Kansas City, Kansas City, MO (J.E.S.); the Division of Critical Care Medicine, Department of Pediatrics, Akron Children's Hospital, Akron (R.A.N.), the Department of Pediatrics, University of Cincinnati College of Medicine, Cincinnati Children's Hospital Medical Center, Cincinnati (M.A.S.), and the Division of Pediatric Critical Care Medicine, Nationwide Children's Hospital Columbus, Columbus (K.E.B.) - all in Ohio; the Division of Critical Care Medicine, Department of Anesthesiology and Critical Care, Children's Hospital of Philadelphia, Philadelphia (K.C.); the Division of Pediatric Critical Care, Department of Pediatrics, Children's Hospital and Medical Center, Omaha, NE (M.L.C.); the Division of Pediatric Critical Care, Department of Pediatrics, Saint Barnabas Medical Center, Livingston, NJ (S.J.G.); the Divisions of Pediatric Infectious Diseases and Pediatric Critical Care Medicine, Department of Pediatric and Adolescent Medicine, Mayo Clinic, Rochester (E.R.L.), and the Division of Pediatric Critical Care, University of Minnesota Masonic Children's Hospital, Minneapolis (J.R.H.) - both in Minnesota; the Division of Pediatric Critical Care Medicine, Department of Pediatrics, University of Alabama at Birmingham, Birmingham (M.K.), the Division of Pediatric Infectious Diseases, Department of Pediatrics, UHealth/Holtz Children's Hospital, Miami (B.M.C.); the Ryan White Center for Pediatric Infectious Disease and Global Health, Department of Pediatrics, Indiana University School of Medicine, Indianapolis (S.S.B.); University of Arizona, Diamond Children's Banner Children's Medical Center, Tucson (M.G.G.); the Department of Pediatrics, Department of Microbiology, Division of Infectious Diseases, University of Mississippi Medical Center, Jackson (C.V.H.); the Department of Pediatrics, Children's Hospital of Michigan, Central Michigan University, Detroit (S.M.H.), and the Division of Pediatric Critical Care Medicine, Department of Pediatrics, Mott Children's Hospital and University of Michigan, Ann Arbor (H.R.F.); and the Division of Critical Care Medicine, Department of Pediatrics, Northwestern University Feinberg School of Medicine, Ann and Robert H. Lurie Children's Hospital of Chicago, Chicago (K.N.M.).; Staat MA; From the Covid-19 Response Team, Centers for Disease Control and Prevention (S.M.O., A.M.P., L.D.Z., A.P.C., M.M.P.), and the Center for Childhood Infections and Vaccines of Children's Healthcare of Atlanta and the Department of Pediatrics, Emory University School of Medicine (S.K.) - both in Atlanta; the Department of Anesthesiology, Critical Care, and Pain Medicine, Boston Children's Hospital (M.M.N., A.G.R.), and the Departments of Anaesthesia and Pediatrics, Harvard Medical School (A.G.R.) - both in Boston; the Division of Pediatric Infectious Diseases, Department of Pediatrics, Vanderbilt University Medical Center, Nashville (N.B.H.); the Department of Pediatrics, Baylor College of Medicine, Immunization Project, Texas Children's Hospital, Houston (J.A.B., L.C.S.), and the Department of Pediatrics, Division of Critical Care Medicine, University of Texas Southwestern, Children's Medical Center Dallas, Dallas (M.M.); the Division of Infectious Diseases, Children's Hospital Los Angeles and Departments of Pediatrics and Molecular Microbiology and Immunology, University of Southern California, Los Angeles (P.S.P.), the Division of Pediatric Hospital Medicine, UC San Diego-Rady Children's Hospital, San Diego (M.A.C.), the Division of Critical Care Medicine, UCSF Benioff Children's Hospital Oakland (N.Z.C.), and the Department of Pediatrics, Divisions of Critical Care Medicine and Allergy, Immunology, and Bone Marrow Transplant, University of California, San Francisco, San Francisco (M.S.Z.) - all in California; Section of Pediatric Critical Care, Department of Pediatrics, Arkansas Children's Hospital, Little Rock (K.I.); the Department of Pediatrics, University of North Carolina at Chapel Hill Children's Hospital, Chapel Hill (T.C.W., S.P.S.); the Department of Pediatrics, Section of Critical Care Medicine, University of Colorado School of Medicine and Children's Hospital Colorado, Aurora (A.B.M.); the Division of Pediatric Critical Care Medicine, Medical University of South Carolina, Charleston (E.H.M.); the Department of Pediatrics, Division of Cardiology, Louisiana State University Health Sciences Center and Children's Hospital of New Orleans, New Orleans (T.T.B.); the Division of Pediatric Infectious Diseases, Department of Pediatrics, Children's Mercy Kansas City, Kansas City, MO (J.E.S.); the Division of Critical Care Medicine, Department of Pediatrics, Akron Children's Hospital, Akron (R.A.N.), the Department of Pediatrics, University of Cincinnati College of Medicine, Cincinnati Children's Hospital Medical Center, Cincinnati (M.A.S.), and the Division of Pediatric Critical Care Medicine, Nationwide Children's Hospital Columbus, Columbus (K.E.B.) - all in Ohio; the Division of Critical Care Medicine, Department of Anesthesiology and Critical Care, Children's Hospital of Philadelphia, Philadelphia (K.C.); the Division of Pediatric Critical Care, Department of Pediatrics, Children's Hospital and Medical Center, Omaha, NE (M.L.C.); the Division of Pediatric Critical Care, Department of Pediatrics, Saint Barnabas Medical Center, Livingston, NJ (S.J.G.); the Divisions of Pediatric Infectious Diseases and Pediatric Critical Care Medicine, Department of Pediatric and Adolescent Medicine, Mayo Clinic, Rochester (E.R.L.), and the Division of Pediatric Critical Care, University of Minnesota Masonic Children's Hospital, Minneapolis (J.R.H.) - both in Minnesota; the Division of Pediatric Critical Care Medicine, Department of Pediatrics, University of Alabama at Birmingham, Birmingham (M.K.), the Division of Pediatric Infectious Diseases, Department of Pediatrics, UHealth/Holtz Children's Hospital, Miami (B.M.C.); the Ryan White Center for Pediatric Infectious Disease and Global Health, Department of Pediatrics, Indiana University School of Medicine, Indianapolis (S.S.B.); University of Arizona, Diamond Children's Banner Children's Medical Center, Tucson (M.G.G.); the Department of Pediatrics, Department of Microbiology, Division of Infectious Diseases, University of Mississippi Medical Center, Jackson (C.V.H.); the Department of Pediatrics, Children's Hospital of Michigan, Central Michigan University, Detroit (S.M.H.), and the Division of Pediatric Critical Care Medicine, Department of Pediatrics, Mott Children's Hospital and University of Michigan, Ann Arbor (H.R.F.); and the Division of Critical Care Medicine, Department of Pediatrics, Northwestern University Feinberg School of Medicine, Ann and Robert H. Lurie Children's Hospital of Chicago, Chicago (K.N.M.).; Kamidani S; From the Covid-19 Response Team, Centers for Disease Control and Prevention (S.M.O., A.M.P., L.D.Z., A.P.C., M.M.P.), and the Center for Childhood Infections and Vaccines of Children's Healthcare of Atlanta and the Department of Pediatrics, Emory University School of Medicine (S.K.) - both in Atlanta; the Department of Anesthesiology, Critical Care, and Pain Medicine, Boston Children's Hospital (M.M.N., A.G.R.), and the Departments of Anaesthesia and Pediatrics, Harvard Medical School (A.G.R.) - both in Boston; the Division of Pediatric Infectious Diseases, Department of Pediatrics, Vanderbilt University Medical Center, Nashville (N.B.H.); the Department of Pediatrics, Baylor College of Medicine, Immunization Project, Texas Children's Hospital, Houston (J.A.B., L.C.S.), and the Department of Pediatrics, Division of Critical Care Medicine, University of Texas Southwestern, Children's Medical Center Dallas, Dallas (M.M.); the Division of Infectious Diseases, Children's Hospital Los Angeles and Departments of Pediatrics and Molecular Microbiology and Immunology, University of Southern California, Los Angeles (P.S.P.), the Division of Pediatric Hospital Medicine, UC San Diego-Rady Children's Hospital, San Diego (M.A.C.), the Division of Critical Care Medicine, UCSF Benioff Children's Hospital Oakland (N.Z.C.), and the Department of Pediatrics, Divisions of Critical Care Medicine and Allergy, Immunology, and Bone Marrow Transplant, University of California, San Francisco, San Francisco (M.S.Z.) - all in California; Section of Pediatric Critical Care, Department of Pediatrics, Arkansas Children's Hospital, Little Rock (K.I.); the Department of Pediatrics, University of North Carolina at Chapel Hill Children's Hospital, Chapel Hill (T.C.W., S.P.S.); the Department of Pediatrics, Section of Critical Care Medicine, University of Colorado School of Medicine and Children's Hospital Colorado, Aurora (A.B.M.); the Division of Pediatric Critical Care Medicine, Medical University of South Carolina, Charleston (E.H.M.); the Department of Pediatrics, Division of Cardiology, Louisiana State University Health Sciences Center and Children's Hospital of New Orleans, New Orleans (T.T.B.); the Division of Pediatric Infectious Diseases, Department of Pediatrics, Children's Mercy Kansas City, Kansas City, MO (J.E.S.); the Division of Critical Care Medicine, Department of Pediatrics, Akron Children's Hospital, Akron (R.A.N.), the Department of Pediatrics, University of Cincinnati College of Medicine, Cincinnati Children's Hospital Medical Center, Cincinnati (M.A.S.), and the Division of Pediatric Critical Care Medicine, Nationwide Children's Hospital Columbus, Columbus (K.E.B.) - all in Ohio; the Division of Critical Care Medicine, Department of Anesthesiology and Critical Care, Children's Hospital of Philadelphia, Philadelphia (K.C.); the Division of Pediatric Critical Care, Department of Pediatrics, Children's Hospital and Medical Center, Omaha, NE (M.L.C.); the Division of Pediatric Critical Care, Department of Pediatrics, Saint Barnabas Medical Center, Livingston, NJ (S.J.G.); the Divisions of Pediatric Infectious Diseases and Pediatric Critical Care Medicine, Department of Pediatric and Adolescent Medicine, Mayo Clinic, Rochester (E.R.L.), and the Division of Pediatric Critical Care, University of Minnesota Masonic Children's Hospital, Minneapolis (J.R.H.) - both in Minnesota; the Division of Pediatric Critical Care Medicine, Department of Pediatrics, University of Alabama at Birmingham, Birmingham (M.K.), the Division of Pediatric Infectious Diseases, Department of Pediatrics, UHealth/Holtz Children's Hospital, Miami (B.M.C.); the Ryan White Center for Pediatric Infectious Disease and Global Health, Department of Pediatrics, Indiana University School of Medicine, Indianapolis (S.S.B.); University of Arizona, Diamond Children's Banner Children's Medical Center, Tucson (M.G.G.); the Department of Pediatrics, Department of Microbiology, Division of Infectious Diseases, University of Mississippi Medical Center, Jackson (C.V.H.); the Department of Pediatrics, Children's Hospital of Michigan, Central Michigan University, Detroit (S.M.H.), and the Division of Pediatric Critical Care Medicine, Department of Pediatrics, Mott Children's Hospital and University of Michigan, Ann Arbor (H.R.F.); and the Division of Critical Care Medicine, Department of Pediatrics, Northwestern University Feinberg School of Medicine, Ann and Robert H. Lurie Children's Hospital of Chicago, Chicago (K.N.M.).; Chatani BM; From the Covid-19 Response Team, Centers for Disease Control and Prevention (S.M.O., A.M.P., L.D.Z., A.P.C., M.M.P.), and the Center for Childhood Infections and Vaccines of Children's Healthcare of Atlanta and the Department of Pediatrics, Emory University School of Medicine (S.K.) - both in Atlanta; the Department of Anesthesiology, Critical Care, and Pain Medicine, Boston Children's Hospital (M.M.N., A.G.R.), and the Departments of Anaesthesia and Pediatrics, Harvard Medical School (A.G.R.) - both in Boston; the Division of Pediatric Infectious Diseases, Department of Pediatrics, Vanderbilt University Medical Center, Nashville (N.B.H.); the Department of Pediatrics, Baylor College of Medicine, Immunization Project, Texas Children's Hospital, Houston (J.A.B., L.C.S.), and the Department of Pediatrics, Division of Critical Care Medicine, University of Texas Southwestern, Children's Medical Center Dallas, Dallas (M.M.); the Division of Infectious Diseases, Children's Hospital Los Angeles and Departments of Pediatrics and Molecular Microbiology and Immunology, University of Southern California, Los Angeles (P.S.P.), the Division of Pediatric Hospital Medicine, UC San Diego-Rady Children's Hospital, San Diego (M.A.C.), the Division of Critical Care Medicine, UCSF Benioff Children's Hospital Oakland (N.Z.C.), and the Department of Pediatrics, Divisions of Critical Care Medicine and Allergy, Immunology, and Bone Marrow Transplant, University of California, San Francisco, San Francisco (M.S.Z.) - all in California; Section of Pediatric Critical Care, Department of Pediatrics, Arkansas Children's Hospital, Little Rock (K.I.); the Department of Pediatrics, University of North Carolina at Chapel Hill Children's Hospital, Chapel Hill (T.C.W., S.P.S.); the Department of Pediatrics, Section of Critical Care Medicine, University of Colorado School of Medicine and Children's Hospital Colorado, Aurora (A.B.M.); the Division of Pediatric Critical Care Medicine, Medical University of South Carolina, Charleston (E.H.M.); the Department of Pediatrics, Division of Cardiology, Louisiana State University Health Sciences Center and Children's Hospital of New Orleans, New Orleans (T.T.B.); the Division of Pediatric Infectious Diseases, Department of Pediatrics, Children's Mercy Kansas City, Kansas City, MO (J.E.S.); the Division of Critical Care Medicine, Department of Pediatrics, Akron Children's Hospital, Akron (R.A.N.), the Department of Pediatrics, University of Cincinnati College of Medicine, Cincinnati Children's Hospital Medical Center, Cincinnati (M.A.S.), and the Division of Pediatric Critical Care Medicine, Nationwide Children's Hospital Columbus, Columbus (K.E.B.) - all in Ohio; the Division of Critical Care Medicine, Department of Anesthesiology and Critical Care, Children's Hospital of Philadelphia, Philadelphia (K.C.); the Division of Pediatric Critical Care, Department of Pediatrics, Children's Hospital and Medical Center, Omaha, NE (M.L.C.); the Division of Pediatric Critical Care, Department of Pediatrics, Saint Barnabas Medical Center, Livingston, NJ (S.J.G.); the Divisions of Pediatric Infectious Diseases and Pediatric Critical Care Medicine, Department of Pediatric and Adolescent Medicine, Mayo Clinic, Rochester (E.R.L.), and the Division of Pediatric Critical Care, University of Minnesota Masonic Children's Hospital, Minneapolis (J.R.H.) - both in Minnesota; the Division of Pediatric Critical Care Medicine, Department of Pediatrics, University of Alabama at Birmingham, Birmingham (M.K.), the Division of Pediatric Infectious Diseases, Department of Pediatrics, UHealth/Holtz Children's Hospital, Miami (B.M.C.); the Ryan White Center for Pediatric Infectious Disease and Global Health, Department of Pediatrics, Indiana University School of Medicine, Indianapolis (S.S.B.); University of Arizona, Diamond Children's Banner Children's Medical Center, Tucson (M.G.G.); the Department of Pediatrics, Department of Microbiology, Division of Infectious Diseases, University of Mississippi Medical Center, Jackson (C.V.H.); the Department of Pediatrics, Children's Hospital of Michigan, Central Michigan University, Detroit (S.M.H.), and the Division of Pediatric Critical Care Medicine, Department of Pediatrics, Mott Children's Hospital and University of Michigan, Ann Arbor (H.R.F.); and the Division of Critical Care Medicine, Department of Pediatrics, Northwestern University Feinberg School of Medicine, Ann and Robert H. Lurie Children's Hospital of Chicago, Chicago (K.N.M.).; Bhumbra SS; From the Covid-19 Response Team, Centers for Disease Control and Prevention (S.M.O., A.M.P., L.D.Z., A.P.C., M.M.P.), and the Center for Childhood Infections and Vaccines of Children's Healthcare of Atlanta and the Department of Pediatrics, Emory University School of Medicine (S.K.) - both in Atlanta; the Department of Anesthesiology, Critical Care, and Pain Medicine, Boston Children's Hospital (M.M.N., A.G.R.), and the Departments of Anaesthesia and Pediatrics, Harvard Medical School (A.G.R.) - both in Boston; the Division of Pediatric Infectious Diseases, Department of Pediatrics, Vanderbilt University Medical Center, Nashville (N.B.H.); the Department of Pediatrics, Baylor College of Medicine, Immunization Project, Texas Children's Hospital, Houston (J.A.B., L.C.S.), and the Department of Pediatrics, Division of Critical Care Medicine, University of Texas Southwestern, Children's Medical Center Dallas, Dallas (M.M.); the Division of Infectious Diseases, Children's Hospital Los Angeles and Departments of Pediatrics and Molecular Microbiology and Immunology, University of Southern California, Los Angeles (P.S.P.), the Division of Pediatric Hospital Medicine, UC San Diego-Rady Children's Hospital, San Diego (M.A.C.), the Division of Critical Care Medicine, UCSF Benioff Children's Hospital Oakland (N.Z.C.), and the Department of Pediatrics, Divisions of Critical Care Medicine and Allergy, Immunology, and Bone Marrow Transplant, University of California, San Francisco, San Francisco (M.S.Z.) - all in California; Section of Pediatric Critical Care, Department of Pediatrics, Arkansas Children's Hospital, Little Rock (K.I.); the Department of Pediatrics, University of North Carolina at Chapel Hill Children's Hospital, Chapel Hill (T.C.W., S.P.S.); the Department of Pediatrics, Section of Critical Care Medicine, University of Colorado School of Medicine and Children's Hospital Colorado, Aurora (A.B.M.); the Division of Pediatric Critical Care Medicine, Medical University of South Carolina, Charleston (E.H.M.); the Department of Pediatrics, Division of Cardiology, Louisiana State University Health Sciences Center and Children's Hospital of New Orleans, New Orleans (T.T.B.); the Division of Pediatric Infectious Diseases, Department of Pediatrics, Children's Mercy Kansas City, Kansas City, MO (J.E.S.); the Division of Critical Care Medicine, Department of Pediatrics, Akron Children's Hospital, Akron (R.A.N.), the Department of Pediatrics, University of Cincinnati College of Medicine, Cincinnati Children's Hospital Medical Center, Cincinnati (M.A.S.), and the Division of Pediatric Critical Care Medicine, Nationwide Children's Hospital Columbus, Columbus (K.E.B.) - all in Ohio; the Division of Critical Care Medicine, Department of Anesthesiology and Critical Care, Children's Hospital of Philadelphia, Philadelphia (K.C.); the Division of Pediatric Critical Care, Department of Pediatrics, Children's Hospital and Medical Center, Omaha, NE (M.L.C.); the Division of Pediatric Critical Care, Department of Pediatrics, Saint Barnabas Medical Center, Livingston, NJ (S.J.G.); the Divisions of Pediatric Infectious Diseases and Pediatric Critical Care Medicine, Department of Pediatric and Adolescent Medicine, Mayo Clinic, Rochester (E.R.L.), and the Division of Pediatric Critical Care, University of Minnesota Masonic Children's Hospital, Minneapolis (J.R.H.) - both in Minnesota; the Division of Pediatric Critical Care Medicine, Department of Pediatrics, University of Alabama at Birmingham, Birmingham (M.K.), the Division of Pediatric Infectious Diseases, Department of Pediatrics, UHealth/Holtz Children's Hospital, Miami (B.M.C.); the Ryan White Center for Pediatric Infectious Disease and Global Health, Department of Pediatrics, Indiana University School of Medicine, Indianapolis (S.S.B.); University of Arizona, Diamond Children's Banner Children's Medical Center, Tucson (M.G.G.); the Department of Pediatrics, Department of Microbiology, Division of Infectious Diseases, University of Mississippi Medical Center, Jackson (C.V.H.); the Department of Pediatrics, Children's Hospital of Michigan, Central Michigan University, Detroit (S.M.H.), and the Division of Pediatric Critical Care Medicine, Department of Pediatrics, Mott Children's Hospital and University of Michigan, Ann Arbor (H.R.F.); and the Division of Critical Care Medicine, Department of Pediatrics, Northwestern University Feinberg School of Medicine, Ann and Robert H. Lurie Children's Hospital of Chicago, Chicago (K.N.M.).; Bline KE; From the Covid-19 Response Team, Centers for Disease Control and Prevention (S.M.O., A.M.P., L.D.Z., A.P.C., M.M.P.), and the Center for Childhood Infections and Vaccines of Children's Healthcare of Atlanta and the Department of Pediatrics, Emory University School of Medicine (S.K.) - both in Atlanta; the Department of Anesthesiology, Critical Care, and Pain Medicine, Boston Children's Hospital (M.M.N., A.G.R.), and the Departments of Anaesthesia and Pediatrics, Harvard Medical School (A.G.R.) - both in Boston; the Division of Pediatric Infectious Diseases, Department of Pediatrics, Vanderbilt University Medical Center, Nashville (N.B.H.); the Department of Pediatrics, Baylor College of Medicine, Immunization Project, Texas Children's Hospital, Houston (J.A.B., L.C.S.), and the Department of Pediatrics, Division of Critical Care Medicine, University of Texas Southwestern, Children's Medical Center Dallas, Dallas (M.M.); the Division of Infectious Diseases, Children's Hospital Los Angeles and Departments of Pediatrics and Molecular Microbiology and Immunology, University of Southern California, Los Angeles (P.S.P.), the Division of Pediatric Hospital Medicine, UC San Diego-Rady Children's Hospital, San Diego (M.A.C.), the Division of Critical Care Medicine, UCSF Benioff Children's Hospital Oakland (N.Z.C.), and the Department of Pediatrics, Divisions of Critical Care Medicine and Allergy, Immunology, and Bone Marrow Transplant, University of California, San Francisco, San Francisco (M.S.Z.) - all in California; Section of Pediatric Critical Care, Department of Pediatrics, Arkansas Children's Hospital, Little Rock (K.I.); the Department of Pediatrics, University of North Carolina at Chapel Hill Children's Hospital, Chapel Hill (T.C.W., S.P.S.); the Department of Pediatrics, Section of Critical Care Medicine, University of Colorado School of Medicine and Children's Hospital Colorado, Aurora (A.B.M.); the Division of Pediatric Critical Care Medicine, Medical University of South Carolina, Charleston (E.H.M.); the Department of Pediatrics, Division of Cardiology, Louisiana State University Health Sciences Center and Children's Hospital of New Orleans, New Orleans (T.T.B.); the Division of Pediatric Infectious Diseases, Department of Pediatrics, Children's Mercy Kansas City, Kansas City, MO (J.E.S.); the Division of Critical Care Medicine, Department of Pediatrics, Akron Children's Hospital, Akron (R.A.N.), the Department of Pediatrics, University of Cincinnati College of Medicine, Cincinnati Children's Hospital Medical Center, Cincinnati (M.A.S.), and the Division of Pediatric Critical Care Medicine, Nationwide Children's Hospital Columbus, Columbus (K.E.B.) - all in Ohio; the Division of Critical Care Medicine, Department of Anesthesiology and Critical Care, Children's Hospital of Philadelphia, Philadelphia (K.C.); the Division of Pediatric Critical Care, Department of Pediatrics, Children's Hospital and Medical Center, Omaha, NE (M.L.C.); the Division of Pediatric Critical Care, Department of Pediatrics, Saint Barnabas Medical Center, Livingston, NJ (S.J.G.); the Divisions of Pediatric Infectious Diseases and Pediatric Critical Care Medicine, Department of Pediatric and Adolescent Medicine, Mayo Clinic, Rochester (E.R.L.), and the Division of Pediatric Critical Care, University of Minnesota Masonic Children's Hospital, Minneapolis (J.R.H.) - both in Minnesota; the Division of Pediatric Critical Care Medicine, Department of Pediatrics, University of Alabama at Birmingham, Birmingham (M.K.), the Division of Pediatric Infectious Diseases, Department of Pediatrics, UHealth/Holtz Children's Hospital, Miami (B.M.C.); the Ryan White Center for Pediatric Infectious Disease and Global Health, Department of Pediatrics, Indiana University School of Medicine, Indianapolis (S.S.B.); University of Arizona, Diamond Children's Banner Children's Medical Center, Tucson (M.G.G.); the Department of Pediatrics, Department of Microbiology, Division of Infectious Diseases, University of Mississippi Medical Center, Jackson (C.V.H.); the Department of Pediatrics, Children's Hospital of Michigan, Central Michigan University, Detroit (S.M.H.), and the Division of Pediatric Critical Care Medicine, Department of Pediatrics, Mott Children's Hospital and University of Michigan, Ann Arbor (H.R.F.); and the Division of Critical Care Medicine, Department of Pediatrics, Northwestern University Feinberg School of Medicine, Ann and Robert H. Lurie Children's Hospital of Chicago, Chicago (K.N.M.).; Gaspers MG; From the Covid-19 Response Team, Centers for Disease Control and Prevention (S.M.O., A.M.P., L.D.Z., A.P.C., M.M.P.), and the Center for Childhood Infections and Vaccines of Children's Healthcare of Atlanta and the Department of Pediatrics, Emory University School of Medicine (S.K.) - both in Atlanta; the Department of Anesthesiology, Critical Care, and Pain Medicine, Boston Children's Hospital (M.M.N., A.G.R.), and the Departments of Anaesthesia and Pediatrics, Harvard Medical School (A.G.R.) - both in Boston; the Division of Pediatric Infectious Diseases, Department of Pediatrics, Vanderbilt University Medical Center, Nashville (N.B.H.); the Department of Pediatrics, Baylor College of Medicine, Immunization Project, Texas Children's Hospital, Houston (J.A.B., L.C.S.), and the Department of Pediatrics, Division of Critical Care Medicine, University of Texas Southwestern, Children's Medical Center Dallas, Dallas (M.M.); the Division of Infectious Diseases, Children's Hospital Los Angeles and Departments of Pediatrics and Molecular Microbiology and Immunology, University of Southern California, Los Angeles (P.S.P.), the Division of Pediatric Hospital Medicine, UC San Diego-Rady Children's Hospital, San Diego (M.A.C.), the Division of Critical Care Medicine, UCSF Benioff Children's Hospital Oakland (N.Z.C.), and the Department of Pediatrics, Divisions of Critical Care Medicine and Allergy, Immunology, and Bone Marrow Transplant, University of California, San Francisco, San Francisco (M.S.Z.) - all in California; Section of Pediatric Critical Care, Department of Pediatrics, Arkansas Children's Hospital, Little Rock (K.I.); the Department of Pediatrics, University of North Carolina at Chapel Hill Children's Hospital, Chapel Hill (T.C.W., S.P.S.); the Department of Pediatrics, Section of Critical Care Medicine, University of Colorado School of Medicine and Children's Hospital Colorado, Aurora (A.B.M.); the Division of Pediatric Critical Care Medicine, Medical University of South Carolina, Charleston (E.H.M.); the Department of Pediatrics, Division of Cardiology, Louisiana State University Health Sciences Center and Children's Hospital of New Orleans, New Orleans (T.T.B.); the Division of Pediatric Infectious Diseases, Department of Pediatrics, Children's Mercy Kansas City, Kansas City, MO (J.E.S.); the Division of Critical Care Medicine, Department of Pediatrics, Akron Children's Hospital, Akron (R.A.N.), the Department of Pediatrics, University of Cincinnati College of Medicine, Cincinnati Children's Hospital Medical Center, Cincinnati (M.A.S.), and the Division of Pediatric Critical Care Medicine, Nationwide Children's Hospital Columbus, Columbus (K.E.B.) - all in Ohio; the Division of Critical Care Medicine, Department of Anesthesiology and Critical Care, Children's Hospital of Philadelphia, Philadelphia (K.C.); the Division of Pediatric Critical Care, Department of Pediatrics, Children's Hospital and Medical Center, Omaha, NE (M.L.C.); the Division of Pediatric Critical Care, Department of Pediatrics, Saint Barnabas Medical Center, Livingston, NJ (S.J.G.); the Divisions of Pediatric Infectious Diseases and Pediatric Critical Care Medicine, Department of Pediatric and Adolescent Medicine, Mayo Clinic, Rochester (E.R.L.), and the Division of Pediatric Critical Care, University of Minnesota Masonic Children's Hospital, Minneapolis (J.R.H.) - both in Minnesota; the Division of Pediatric Critical Care Medicine, Department of Pediatrics, University of Alabama at Birmingham, Birmingham (M.K.), the Division of Pediatric Infectious Diseases, Department of Pediatrics, UHealth/Holtz Children's Hospital, Miami (B.M.C.); the Ryan White Center for Pediatric Infectious Disease and Global Health, Department of Pediatrics, Indiana University School of Medicine, Indianapolis (S.S.B.); University of Arizona, Diamond Children's Banner Children's Medical Center, Tucson (M.G.G.); the Department of Pediatrics, Department of Microbiology, Division of Infectious Diseases, University of Mississippi Medical Center, Jackson (C.V.H.); the Department of Pediatrics, Children's Hospital of Michigan, Central Michigan University, Detroit (S.M.H.), and the Division of Pediatric Critical Care Medicine, Department of Pediatrics, Mott Children's Hospital and University of Michigan, Ann Arbor (H.R.F.); and the Division of Critical Care Medicine, Department of Pediatrics, Northwestern University Feinberg School of Medicine, Ann and Robert H. Lurie Children's Hospital of Chicago, Chicago (K.N.M.).; Hobbs CV; From the Covid-19 Response Team, Centers for Disease Control and Prevention (S.M.O., A.M.P., L.D.Z., A.P.C., M.M.P.), and the Center for Childhood Infections and Vaccines of Children's Healthcare of Atlanta and the Department of Pediatrics, Emory University School of Medicine (S.K.) - both in Atlanta; the Department of Anesthesiology, Critical Care, and Pain Medicine, Boston Children's Hospital (M.M.N., A.G.R.), and the Departments of Anaesthesia and Pediatrics, Harvard Medical School (A.G.R.) - both in Boston; the Division of Pediatric Infectious Diseases, Department of Pediatrics, Vanderbilt University Medical Center, Nashville (N.B.H.); the Department of Pediatrics, Baylor College of Medicine, Immunization Project, Texas Children's Hospital, Houston (J.A.B., L.C.S.), and the Department of Pediatrics, Division of Critical Care Medicine, University of Texas Southwestern, Children's Medical Center Dallas, Dallas (M.M.); the Division of Infectious Diseases, Children's Hospital Los Angeles and Departments of Pediatrics and Molecular Microbiology and Immunology, University of Southern California, Los Angeles (P.S.P.), the Division of Pediatric Hospital Medicine, UC San Diego-Rady Children's Hospital, San Diego (M.A.C.), the Division of Critical Care Medicine, UCSF Benioff Children's Hospital Oakland (N.Z.C.), and the Department of Pediatrics, Divisions of Critical Care Medicine and Allergy, Immunology, and Bone Marrow Transplant, University of California, San Francisco, San Francisco (M.S.Z.) - all in California; Section of Pediatric Critical Care, Department of Pediatrics, Arkansas Children's Hospital, Little Rock (K.I.); the Department of Pediatrics, University of North Carolina at Chapel Hill Children's Hospital, Chapel Hill (T.C.W., S.P.S.); the Department of Pediatrics, Section of Critical Care Medicine, University of Colorado School of Medicine and Children's Hospital Colorado, Aurora (A.B.M.); the Division of Pediatric Critical Care Medicine, Medical University of South Carolina, Charleston (E.H.M.); the Department of Pediatrics, Division of Cardiology, Louisiana State University Health Sciences Center and Children's Hospital of New Orleans, New Orleans (T.T.B.); the Division of Pediatric Infectious Diseases, Department of Pediatrics, Children's Mercy Kansas City, Kansas City, MO (J.E.S.); the Division of Critical Care Medicine, Department of Pediatrics, Akron Children's Hospital, Akron (R.A.N.), the Department of Pediatrics, University of Cincinnati College of Medicine, Cincinnati Children's Hospital Medical Center, Cincinnati (M.A.S.), and the Division of Pediatric Critical Care Medicine, Nationwide Children's Hospital Columbus, Columbus (K.E.B.) - all in Ohio; the Division of Critical Care Medicine, Department of Anesthesiology and Critical Care, Children's Hospital of Philadelphia, Philadelphia (K.C.); the Division of Pediatric Critical Care, Department of Pediatrics, Children's Hospital and Medical Center, Omaha, NE (M.L.C.); the Division of Pediatric Critical Care, Department of Pediatrics, Saint Barnabas Medical Center, Livingston, NJ (S.J.G.); the Divisions of Pediatric Infectious Diseases and Pediatric Critical Care Medicine, Department of Pediatric and Adolescent Medicine, Mayo Clinic, Rochester (E.R.L.), and the Division of Pediatric Critical Care, University of Minnesota Masonic Children's Hospital, Minneapolis (J.R.H.) - both in Minnesota; the Division of Pediatric Critical Care Medicine, Department of Pediatrics, University of Alabama at Birmingham, Birmingham (M.K.), the Division of Pediatric Infectious Diseases, Department of Pediatrics, UHealth/Holtz Children's Hospital, Miami (B.M.C.); the Ryan White Center for Pediatric Infectious Disease and Global Health, Department of Pediatrics, Indiana University School of Medicine, Indianapolis (S.S.B.); University of Arizona, Diamond Children's Banner Children's Medical Center, Tucson (M.G.G.); the Department of Pediatrics, Department of Microbiology, Division of Infectious Diseases, University of Mississippi Medical Center, Jackson (C.V.H.); the Department of Pediatrics, Children's Hospital of Michigan, Central Michigan University, Detroit (S.M.H.), and the Division of Pediatric Critical Care Medicine, Department of Pediatrics, Mott Children's Hospital and University of Michigan, Ann Arbor (H.R.F.); and the Division of Critical Care Medicine, Department of Pediatrics, Northwestern University Feinberg School of Medicine, Ann and Robert H. Lurie Children's Hospital of Chicago, Chicago (K.N.M.).; Heidemann SM; From the Covid-19 Response Team, Centers for Disease Control and Prevention (S.M.O., A.M.P., L.D.Z., A.P.C., M.M.P.), and the Center for Childhood Infections and Vaccines of Children's Healthcare of Atlanta and the Department of Pediatrics, Emory University School of Medicine (S.K.) - both in Atlanta; the Department of Anesthesiology, Critical Care, and Pain Medicine, Boston Children's Hospital (M.M.N., A.G.R.), and the Departments of Anaesthesia and Pediatrics, Harvard Medical School (A.G.R.) - both in Boston; the Division of Pediatric Infectious Diseases, Department of Pediatrics, Vanderbilt University Medical Center, Nashville (N.B.H.); the Department of Pediatrics, Baylor College of Medicine, Immunization Project, Texas Children's Hospital, Houston (J.A.B., L.C.S.), and the Department of Pediatrics, Division of Critical Care Medicine, University of Texas Southwestern, Children's Medical Center Dallas, Dallas (M.M.); the Division of Infectious Diseases, Children's Hospital Los Angeles and Departments of Pediatrics and Molecular Microbiology and Immunology, University of Southern California, Los Angeles (P.S.P.), the Division of Pediatric Hospital Medicine, UC San Diego-Rady Children's Hospital, San Diego (M.A.C.), the Division of Critical Care Medicine, UCSF Benioff Children's Hospital Oakland (N.Z.C.), and the Department of Pediatrics, Divisions of Critical Care Medicine and Allergy, Immunology, and Bone Marrow Transplant, University of California, San Francisco, San Francisco (M.S.Z.) - all in California; Section of Pediatric Critical Care, Department of Pediatrics, Arkansas Children's Hospital, Little Rock (K.I.); the Department of Pediatrics, University of North Carolina at Chapel Hill Children's Hospital, Chapel Hill (T.C.W., S.P.S.); the Department of Pediatrics, Section of Critical Care Medicine, University of Colorado School of Medicine and Children's Hospital Colorado, Aurora (A.B.M.); the Division of Pediatric Critical Care Medicine, Medical University of South Carolina, Charleston (E.H.M.); the Department of Pediatrics, Division of Cardiology, Louisiana State University Health Sciences Center and Children's Hospital of New Orleans, New Orleans (T.T.B.); the Division of Pediatric Infectious Diseases, Department of Pediatrics, Children's Mercy Kansas City, Kansas City, MO (J.E.S.); the Division of Critical Care Medicine, Department of Pediatrics, Akron Children's Hospital, Akron (R.A.N.), the Department of Pediatrics, University of Cincinnati College of Medicine, Cincinnati Children's Hospital Medical Center, Cincinnati (M.A.S.), and the Division of Pediatric Critical Care Medicine, Nationwide Children's Hospital Columbus, Columbus (K.E.B.) - all in Ohio; the Division of Critical Care Medicine, Department of Anesthesiology and Critical Care, Children's Hospital of Philadelphia, Philadelphia (K.C.); the Division of Pediatric Critical Care, Department of Pediatrics, Children's Hospital and Medical Center, Omaha, NE (M.L.C.); the Division of Pediatric Critical Care, Department of Pediatrics, Saint Barnabas Medical Center, Livingston, NJ (S.J.G.); the Divisions of Pediatric Infectious Diseases and Pediatric Critical Care Medicine, Department of Pediatric and Adolescent Medicine, Mayo Clinic, Rochester (E.R.L.), and the Division of Pediatric Critical Care, University of Minnesota Masonic Children's Hospital, Minneapolis (J.R.H.) - both in Minnesota; the Division of Pediatric Critical Care Medicine, Department of Pediatrics, University of Alabama at Birmingham, Birmingham (M.K.), the Division of Pediatric Infectious Diseases, Department of Pediatrics, UHealth/Holtz Children's Hospital, Miami (B.M.C.); the Ryan White Center for Pediatric Infectious Disease and Global Health, Department of Pediatrics, Indiana University School of Medicine, Indianapolis (S.S.B.); University of Arizona, Diamond Children's Banner Children's Medical Center, Tucson (M.G.G.); the Department of Pediatrics, Department of Microbiology, Division of Infectious Diseases, University of Mississippi Medical Center, Jackson (C.V.H.); the Department of Pediatrics, Children's Hospital of Michigan, Central Michigan University, Detroit (S.M.H.), and the Division of Pediatric Critical Care Medicine, Department of Pediatrics, Mott Children's Hospital and University of Michigan, Ann Arbor (H.R.F.); and the Division of Critical Care Medicine, Department of Pediatrics, Northwestern University Feinberg School of Medicine, Ann and Robert H. Lurie Children's Hospital of Chicago, Chicago (K.N.M.).; Maamari M; From the Covid-19 Response Team, Centers for Disease Control and Prevention (S.M.O., A.M.P., L.D.Z., A.P.C., M.M.P.), and the Center for Childhood Infections and Vaccines of Children's Healthcare of Atlanta and the Department of Pediatrics, Emory University School of Medicine (S.K.) - both in Atlanta; the Department of Anesthesiology, Critical Care, and Pain Medicine, Boston Children's Hospital (M.M.N., A.G.R.), and the Departments of Anaesthesia and Pediatrics, Harvard Medical School (A.G.R.) - both in Boston; the Division of Pediatric Infectious Diseases, Department of Pediatrics, Vanderbilt University Medical Center, Nashville (N.B.H.); the Department of Pediatrics, Baylor College of Medicine, Immunization Project, Texas Children's Hospital, Houston (J.A.B., L.C.S.), and the Department of Pediatrics, Division of Critical Care Medicine, University of Texas Southwestern, Children's Medical Center Dallas, Dallas (M.M.); the Division of Infectious Diseases, Children's Hospital Los Angeles and Departments of Pediatrics and Molecular Microbiology and Immunology, University of Southern California, Los Angeles (P.S.P.), the Division of Pediatric Hospital Medicine, UC San Diego-Rady Children's Hospital, San Diego (M.A.C.), the Division of Critical Care Medicine, UCSF Benioff Children's Hospital Oakland (N.Z.C.), and the Department of Pediatrics, Divisions of Critical Care Medicine and Allergy, Immunology, and Bone Marrow Transplant, University of California, San Francisco, San Francisco (M.S.Z.) - all in California; Section of Pediatric Critical Care, Department of Pediatrics, Arkansas Children's Hospital, Little Rock (K.I.); the Department of Pediatrics, University of North Carolina at Chapel Hill Children's Hospital, Chapel Hill (T.C.W., S.P.S.); the Department of Pediatrics, Section of Critical Care Medicine, University of Colorado School of Medicine and Children's Hospital Colorado, Aurora (A.B.M.); the Division of Pediatric Critical Care Medicine, Medical University of South Carolina, Charleston (E.H.M.); the Department of Pediatrics, Division of Cardiology, Louisiana State University Health Sciences Center and Children's Hospital of New Orleans, New Orleans (T.T.B.); the Division of Pediatric Infectious Diseases, Department of Pediatrics, Children's Mercy Kansas City, Kansas City, MO (J.E.S.); the Division of Critical Care Medicine, Department of Pediatrics, Akron Children's Hospital, Akron (R.A.N.), the Department of Pediatrics, University of Cincinnati College of Medicine, Cincinnati Children's Hospital Medical Center, Cincinnati (M.A.S.), and the Division of Pediatric Critical Care Medicine, Nationwide Children's Hospital Columbus, Columbus (K.E.B.) - all in Ohio; the Division of Critical Care Medicine, Department of Anesthesiology and Critical Care, Children's Hospital of Philadelphia, Philadelphia (K.C.); the Division of Pediatric Critical Care, Department of Pediatrics, Children's Hospital and Medical Center, Omaha, NE (M.L.C.); the Division of Pediatric Critical Care, Department of Pediatrics, Saint Barnabas Medical Center, Livingston, NJ (S.J.G.); the Divisions of Pediatric Infectious Diseases and Pediatric Critical Care Medicine, Department of Pediatric and Adolescent Medicine, Mayo Clinic, Rochester (E.R.L.), and the Division of Pediatric Critical Care, University of Minnesota Masonic Children's Hospital, Minneapolis (J.R.H.) - both in Minnesota; the Division of Pediatric Critical Care Medicine, Department of Pediatrics, University of Alabama at Birmingham, Birmingham (M.K.), the Division of Pediatric Infectious Diseases, Department of Pediatrics, UHealth/Holtz Children's Hospital, Miami (B.M.C.); the Ryan White Center for Pediatric Infectious Disease and Global Health, Department of Pediatrics, Indiana University School of Medicine, Indianapolis (S.S.B.); University of Arizona, Diamond Children's Banner Children's Medical Center, Tucson (M.G.G.); the Department of Pediatrics, Department of Microbiology, Division of Infectious Diseases, University of Mississippi Medical Center, Jackson (C.V.H.); the Department of Pediatrics, Children's Hospital of Michigan, Central Michigan University, Detroit (S.M.H.), and the Division of Pediatric Critical Care Medicine, Department of Pediatrics, Mott Children's Hospital and University of Michigan, Ann Arbor (H.R.F.); and the Division of Critical Care Medicine, Department of Pediatrics, Northwestern University Feinberg School of Medicine, Ann and Robert H. Lurie Children's Hospital of Chicago, Chicago (K.N.M.).; Flori HR; From the Covid-19 Response Team, Centers for Disease Control and Prevention (S.M.O., A.M.P., L.D.Z., A.P.C., M.M.P.), and the Center for Childhood Infections and Vaccines of Children's Healthcare of Atlanta and the Department of Pediatrics, Emory University School of Medicine (S.K.) - both in Atlanta; the Department of Anesthesiology, Critical Care, and Pain Medicine, Boston Children's Hospital (M.M.N., A.G.R.), and the Departments of Anaesthesia and Pediatrics, Harvard Medical School (A.G.R.) - both in Boston; the Division of Pediatric Infectious Diseases, Department of Pediatrics, Vanderbilt University Medical Center, Nashville (N.B.H.); the Department of Pediatrics, Baylor College of Medicine, Immunization Project, Texas Children's Hospital, Houston (J.A.B., L.C.S.), and the Department of Pediatrics, Division of Critical Care Medicine, University of Texas Southwestern, Children's Medical Center Dallas, Dallas (M.M.); the Division of Infectious Diseases, Children's Hospital Los Angeles and Departments of Pediatrics and Molecular Microbiology and Immunology, University of Southern California, Los Angeles (P.S.P.), the Division of Pediatric Hospital Medicine, UC San Diego-Rady Children's Hospital, San Diego (M.A.C.), the Division of Critical Care Medicine, UCSF Benioff Children's Hospital Oakland (N.Z.C.), and the Department of Pediatrics, Divisions of Critical Care Medicine and Allergy, Immunology, and Bone Marrow Transplant, University of California, San Francisco, San Francisco (M.S.Z.) - all in California; Section of Pediatric Critical Care, Department of Pediatrics, Arkansas Children's Hospital, Little Rock (K.I.); the Department of Pediatrics, University of North Carolina at Chapel Hill Children's Hospital, Chapel Hill (T.C.W., S.P.S.); the Department of Pediatrics, Section of Critical Care Medicine, University of Colorado School of Medicine and Children's Hospital Colorado, Aurora (A.B.M.); the Division of Pediatric Critical Care Medicine, Medical University of South Carolina, Charleston (E.H.M.); the Department of Pediatrics, Division of Cardiology, Louisiana State University Health Sciences Center and Children's Hospital of New Orleans, New Orleans (T.T.B.); the Division of Pediatric Infectious Diseases, Department of Pediatrics, Children's Mercy Kansas City, Kansas City, MO (J.E.S.); the Division of Critical Care Medicine, Department of Pediatrics, Akron Children's Hospital, Akron (R.A.N.), the Department of Pediatrics, University of Cincinnati College of Medicine, Cincinnati Children's Hospital Medical Center, Cincinnati (M.A.S.), and the Division of Pediatric Critical Care Medicine, Nationwide Children's Hospital Columbus, Columbus (K.E.B.) - all in Ohio; the Division of Critical Care Medicine, Department of Anesthesiology and Critical Care, Children's Hospital of Philadelphia, Philadelphia (K.C.); the Division of Pediatric Critical Care, Department of Pediatrics, Children's Hospital and Medical Center, Omaha, NE (M.L.C.); the Division of Pediatric Critical Care, Department of Pediatrics, Saint Barnabas Medical Center, Livingston, NJ (S.J.G.); the Divisions of Pediatric Infectious Diseases and Pediatric Critical Care Medicine, Department of Pediatric and Adolescent Medicine, Mayo Clinic, Rochester (E.R.L.), and the Division of Pediatric Critical Care, University of Minnesota Masonic Children's Hospital, Minneapolis (J.R.H.) - both in Minnesota; the Division of Pediatric Critical Care Medicine, Department of Pediatrics, University of Alabama at Birmingham, Birmingham (M.K.), the Division of Pediatric Infectious Diseases, Department of Pediatrics, UHealth/Holtz Children's Hospital, Miami (B.M.C.); the Ryan White Center for Pediatric Infectious Disease and Global Health, Department of Pediatrics, Indiana University School of Medicine, Indianapolis (S.S.B.); University of Arizona, Diamond Children's Banner Children's Medical Center, Tucson (M.G.G.); the Department of Pediatrics, Department of Microbiology, Division of Infectious Diseases, University of Mississippi Medical Center, Jackson (C.V.H.); the Department of Pediatrics, Children's Hospital of Michigan, Central Michigan University, Detroit (S.M.H.), and the Division of Pediatric Critical Care Medicine, Department of Pediatrics, Mott Children's Hospital and University of Michigan, Ann Arbor (H.R.F.); and the Division of Critical Care Medicine, Department of Pediatrics, Northwestern University Feinberg School of Medicine, Ann and Robert H. Lurie Children's Hospital of Chicago, Chicago (K.N.M.).; Hume JR; From the Covid-19 Response Team, Centers for Disease Control and Prevention (S.M.O., A.M.P., L.D.Z., A.P.C., M.M.P.), and the Center for Childhood Infections and Vaccines of Children's Healthcare of Atlanta and the Department of Pediatrics, Emory University School of Medicine (S.K.) - both in Atlanta; the Department of Anesthesiology, Critical Care, and Pain Medicine, Boston Children's Hospital (M.M.N., A.G.R.), and the Departments of Anaesthesia and Pediatrics, Harvard Medical School (A.G.R.) - both in Boston; the Division of Pediatric Infectious Diseases, Department of Pediatrics, Vanderbilt University Medical Center, Nashville (N.B.H.); the Department of Pediatrics, Baylor College of Medicine, Immunization Project, Texas Children's Hospital, Houston (J.A.B., L.C.S.), and the Department of Pediatrics, Division of Critical Care Medicine, University of Texas Southwestern, Children's Medical Center Dallas, Dallas (M.M.); the Division of Infectious Diseases, Children's Hospital Los Angeles and Departments of Pediatrics and Molecular Microbiology and Immunology, University of Southern California, Los Angeles (P.S.P.), the Division of Pediatric Hospital Medicine, UC San Diego-Rady Children's Hospital, San Diego (M.A.C.), the Division of Critical Care Medicine, UCSF Benioff Children's Hospital Oakland (N.Z.C.), and the Department of Pediatrics, Divisions of Critical Care Medicine and Allergy, Immunology, and Bone Marrow Transplant, University of California, San Francisco, San Francisco (M.S.Z.) - all in California; Section of Pediatric Critical Care, Department of Pediatrics, Arkansas Children's Hospital, Little Rock (K.I.); the Department of Pediatrics, University of North Carolina at Chapel Hill Children's Hospital, Chapel Hill (T.C.W., S.P.S.); the Department of Pediatrics, Section of Critical Care Medicine, University of Colorado School of Medicine and Children's Hospital Colorado, Aurora (A.B.M.); the Division of Pediatric Critical Care Medicine, Medical University of South Carolina, Charleston (E.H.M.); the Department of Pediatrics, Division of Cardiology, Louisiana State University Health Sciences Center and Children's Hospital of New Orleans, New Orleans (T.T.B.); the Division of Pediatric Infectious Diseases, Department of Pediatrics, Children's Mercy Kansas City, Kansas City, MO (J.E.S.); the Division of Critical Care Medicine, Department of Pediatrics, Akron Children's Hospital, Akron (R.A.N.), the Department of Pediatrics, University of Cincinnati College of Medicine, Cincinnati Children's Hospital Medical Center, Cincinnati (M.A.S.), and the Division of Pediatric Critical Care Medicine, Nationwide Children's Hospital Columbus, Columbus (K.E.B.) - all in Ohio; the Division of Critical Care Medicine, Department of Anesthesiology and Critical Care, Children's Hospital of Philadelphia, Philadelphia (K.C.); the Division of Pediatric Critical Care, Department of Pediatrics, Children's Hospital and Medical Center, Omaha, NE (M.L.C.); the Division of Pediatric Critical Care, Department of Pediatrics, Saint Barnabas Medical Center, Livingston, NJ (S.J.G.); the Divisions of Pediatric Infectious Diseases and Pediatric Critical Care Medicine, Department of Pediatric and Adolescent Medicine, Mayo Clinic, Rochester (E.R.L.), and the Division of Pediatric Critical Care, University of Minnesota Masonic Children's Hospital, Minneapolis (J.R.H.) - both in Minnesota; the Division of Pediatric Critical Care Medicine, Department of Pediatrics, University of Alabama at Birmingham, Birmingham (M.K.), the Division of Pediatric Infectious Diseases, Department of Pediatrics, UHealth/Holtz Children's Hospital, Miami (B.M.C.); the Ryan White Center for Pediatric Infectious Disease and Global Health, Department of Pediatrics, Indiana University School of Medicine, Indianapolis (S.S.B.); University of Arizona, Diamond Children's Banner Children's Medical Center, Tucson (M.G.G.); the Department of Pediatrics, Department of Microbiology, Division of Infectious Diseases, University of Mississippi Medical Center, Jackson (C.V.H.); the Department of Pediatrics, Children's Hospital of Michigan, Central Michigan University, Detroit (S.M.H.), and the Division of Pediatric Critical Care Medicine, Department of Pediatrics, Mott Children's Hospital and University of Michigan, Ann Arbor (H.R.F.); and the Division of Critical Care Medicine, Department of Pediatrics, Northwestern University Feinberg School of Medicine, Ann and Robert H. Lurie Children's Hospital of Chicago, Chicago (K.N.M.).; Zinter MS; From the Covid-19 Response Team, Centers for Disease Control and Prevention (S.M.O., A.M.P., L.D.Z., A.P.C., M.M.P.), and the Center for Childhood Infections and Vaccines of Children's Healthcare of Atlanta and the Department of Pediatrics, Emory University School of Medicine (S.K.) - both in Atlanta; the Department of Anesthesiology, Critical Care, and Pain Medicine, Boston Children's Hospital (M.M.N., A.G.R.), and the Departments of Anaesthesia and Pediatrics, Harvard Medical School (A.G.R.) - both in Boston; the Division of Pediatric Infectious Diseases, Department of Pediatrics, Vanderbilt University Medical Center, Nashville (N.B.H.); the Department of Pediatrics, Baylor College of Medicine, Immunization Project, Texas Children's Hospital, Houston (J.A.B., L.C.S.), and the Department of Pediatrics, Division of Critical Care Medicine, University of Texas Southwestern, Children's Medical Center Dallas, Dallas (M.M.); the Division of Infectious Diseases, Children's Hospital Los Angeles and Departments of Pediatrics and Molecular Microbiology and Immunology, University of Southern California, Los Angeles (P.S.P.), the Division of Pediatric Hospital Medicine, UC San Diego-Rady Children's Hospital, San Diego (M.A.C.), the Division of Critical Care Medicine, UCSF Benioff Children's Hospital Oakland (N.Z.C.), and the Department of Pediatrics, Divisions of Critical Care Medicine and Allergy, Immunology, and Bone Marrow Transplant, University of California, San Francisco, San Francisco (M.S.Z.) - all in California; Section of Pediatric Critical Care, Department of Pediatrics, Arkansas Children's Hospital, Little Rock (K.I.); the Department of Pediatrics, University of North Carolina at Chapel Hill Children's Hospital, Chapel Hill (T.C.W., S.P.S.); the Department of Pediatrics, Section of Critical Care Medicine, University of Colorado School of Medicine and Children's Hospital Colorado, Aurora (A.B.M.); the Division of Pediatric Critical Care Medicine, Medical University of South Carolina, Charleston (E.H.M.); the Department of Pediatrics, Division of Cardiology, Louisiana State University Health Sciences Center and Children's Hospital of New Orleans, New Orleans (T.T.B.); the Division of Pediatric Infectious Diseases, Department of Pediatrics, Children's Mercy Kansas City, Kansas City, MO (J.E.S.); the Division of Critical Care Medicine, Department of Pediatrics, Akron Children's Hospital, Akron (R.A.N.), the Department of Pediatrics, University of Cincinnati College of Medicine, Cincinnati Children's Hospital Medical Center, Cincinnati (M.A.S.), and the Division of Pediatric Critical Care Medicine, Nationwide Children's Hospital Columbus, Columbus (K.E.B.) - all in Ohio; the Division of Critical Care Medicine, Department of Anesthesiology and Critical Care, Children's Hospital of Philadelphia, Philadelphia (K.C.); the Division of Pediatric Critical Care, Department of Pediatrics, Children's Hospital and Medical Center, Omaha, NE (M.L.C.); the Division of Pediatric Critical Care, Department of Pediatrics, Saint Barnabas Medical Center, Livingston, NJ (S.J.G.); the Divisions of Pediatric Infectious Diseases and Pediatric Critical Care Medicine, Department of Pediatric and Adolescent Medicine, Mayo Clinic, Rochester (E.R.L.), and the Division of Pediatric Critical Care, University of Minnesota Masonic Children's Hospital, Minneapolis (J.R.H.) - both in Minnesota; the Division of Pediatric Critical Care Medicine, Department of Pediatrics, University of Alabama at Birmingham, Birmingham (M.K.), the Division of Pediatric Infectious Diseases, Department of Pediatrics, UHealth/Holtz Children's Hospital, Miami (B.M.C.); the Ryan White Center for Pediatric Infectious Disease and Global Health, Department of Pediatrics, Indiana University School of Medicine, Indianapolis (S.S.B.); University of Arizona, Diamond Children's Banner Children's Medical Center, Tucson (M.G.G.); the Department of Pediatrics, Department of Microbiology, Division of Infectious Diseases, University of Mississippi Medical Center, Jackson (C.V.H.); the Department of Pediatrics, Children's Hospital of Michigan, Central Michigan University, Detroit (S.M.H.), and the Division of Pediatric Critical Care Medicine, Department of Pediatrics, Mott Children's Hospital and University of Michigan, Ann Arbor (H.R.F.); and the Division of Critical Care Medicine, Department of Pediatrics, Northwestern University Feinberg School of Medicine, Ann and Robert H. Lurie Children's Hospital of Chicago, Chicago (K.N.M.).; Michelson KN; From the Covid-19 Response Team, Centers for Disease Control and Prevention (S.M.O., A.M.P., L.D.Z., A.P.C., M.M.P.), and the Center for Childhood Infections and Vaccines of Children's Healthcare of Atlanta and the Department of Pediatrics, Emory University School of Medicine (S.K.) - both in Atlanta; the Department of Anesthesiology, Critical Care, and Pain Medicine, Boston Children's Hospital (M.M.N., A.G.R.), and the Departments of Anaesthesia and Pediatrics, Harvard Medical School (A.G.R.) - both in Boston; the Division of Pediatric Infectious Diseases, Department of Pediatrics, Vanderbilt University Medical Center, Nashville (N.B.H.); the Department of Pediatrics, Baylor College of Medicine, Immunization Project, Texas Children's Hospital, Houston (J.A.B., L.C.S.), and the Department of Pediatrics, Division of Critical Care Medicine, University of Texas Southwestern, Children's Medical Center Dallas, Dallas (M.M.); the Division of Infectious Diseases, Children's Hospital Los Angeles and Departments of Pediatrics and Molecular Microbiology and Immunology, University of Southern California, Los Angeles (P.S.P.), the Division of Pediatric Hospital Medicine, UC San Diego-Rady Children's Hospital, San Diego (M.A.C.), the Division of Critical Care Medicine, UCSF Benioff Children's Hospital Oakland (N.Z.C.), and the Department of Pediatrics, Divisions of Critical Care Medicine and Allergy, Immunology, and Bone Marrow Transplant, University of California, San Francisco, San Francisco (M.S.Z.) - all in California; Section of Pediatric Critical Care, Department of Pediatrics, Arkansas Children's Hospital, Little Rock (K.I.); the Department of Pediatrics, University of North Carolina at Chapel Hill Children's Hospital, Chapel Hill (T.C.W., S.P.S.); the Department of Pediatrics, Section of Critical Care Medicine, University of Colorado School of Medicine and Children's Hospital Colorado, Aurora (A.B.M.); the Division of Pediatric Critical Care Medicine, Medical University of South Carolina, Charleston (E.H.M.); the Department of Pediatrics, Division of Cardiology, Louisiana State University Health Sciences Center and Children's Hospital of New Orleans, New Orleans (T.T.B.); the Division of Pediatric Infectious Diseases, Department of Pediatrics, Children's Mercy Kansas City, Kansas City, MO (J.E.S.); the Division of Critical Care Medicine, Department of Pediatrics, Akron Children's Hospital, Akron (R.A.N.), the Department of Pediatrics, University of Cincinnati College of Medicine, Cincinnati Children's Hospital Medical Center, Cincinnati (M.A.S.), and the Division of Pediatric Critical Care Medicine, Nationwide Children's Hospital Columbus, Columbus (K.E.B.) - all in Ohio; the Division of Critical Care Medicine, Department of Anesthesiology and Critical Care, Children's Hospital of Philadelphia, Philadelphia (K.C.); the Division of Pediatric Critical Care, Department of Pediatrics, Children's Hospital and Medical Center, Omaha, NE (M.L.C.); the Division of Pediatric Critical Care, Department of Pediatrics, Saint Barnabas Medical Center, Livingston, NJ (S.J.G.); the Divisions of Pediatric Infectious Diseases and Pediatric Critical Care Medicine, Department of Pediatric and Adolescent Medicine, Mayo Clinic, Rochester (E.R.L.), and the Division of Pediatric Critical Care, University of Minnesota Masonic Children's Hospital, Minneapolis (J.R.H.) - both in Minnesota; the Division of Pediatric Critical Care Medicine, Department of Pediatrics, University of Alabama at Birmingham, Birmingham (M.K.), the Division of Pediatric Infectious Diseases, Department of Pediatrics, UHealth/Holtz Children's Hospital, Miami (B.M.C.); the Ryan White Center for Pediatric Infectious Disease and Global Health, Department of Pediatrics, Indiana University School of Medicine, Indianapolis (S.S.B.); University of Arizona, Diamond Children's Banner Children's Medical Center, Tucson (M.G.G.); the Department of Pediatrics, Department of Microbiology, Division of Infectious Diseases, University of Mississippi Medical Center, Jackson (C.V.H.); the Department of Pediatrics, Children's Hospital of Michigan, Central Michigan University, Detroit (S.M.H.), and the Division of Pediatric Critical Care Medicine, Department of Pediatrics, Mott Children's Hospital and University of Michigan, Ann Arbor (H.R.F.); and the Division of Critical Care Medicine, Department of Pediatrics, Northwestern University Feinberg School of Medicine, Ann and Robert H. Lurie Children's Hospital of Chicago, Chicago (K.N.M.).; Zambrano LD; From the Covid-19 Response Team, Centers for Disease Control and Prevention (S.M.O., A.M.P., L.D.Z., A.P.C., M.M.P.), and the Center for Childhood Infections and Vaccines of Children's Healthcare of Atlanta and the Department of Pediatrics, Emory University School of Medicine (S.K.) - both in Atlanta; the Department of Anesthesiology, Critical Care, and Pain Medicine, Boston Children's Hospital (M.M.N., A.G.R.), and the Departments of Anaesthesia and Pediatrics, Harvard Medical School (A.G.R.) - both in Boston; the Division of Pediatric Infectious Diseases, Department of Pediatrics, Vanderbilt University Medical Center, Nashville (N.B.H.); the Department of Pediatrics, Baylor College of Medicine, Immunization Project, Texas Children's Hospital, Houston (J.A.B., L.C.S.), and the Department of Pediatrics, Division of Critical Care Medicine, University of Texas Southwestern, Children's Medical Center Dallas, Dallas (M.M.); the Division of Infectious Diseases, Children's Hospital Los Angeles and Departments of Pediatrics and Molecular Microbiology and Immunology, University of Southern California, Los Angeles (P.S.P.), the Division of Pediatric Hospital Medicine, UC San Diego-Rady Children's Hospital, San Diego (M.A.C.), the Division of Critical Care Medicine, UCSF Benioff Children's Hospital Oakland (N.Z.C.), and the Department of Pediatrics, Divisions of Critical Care Medicine and Allergy, Immunology, and Bone Marrow Transplant, University of California, San Francisco, San Francisco (M.S.Z.) - all in California; Section of Pediatric Critical Care, Department of Pediatrics, Arkansas Children's Hospital, Little Rock (K.I.); the Department of Pediatrics, University of North Carolina at Chapel Hill Children's Hospital, Chapel Hill (T.C.W., S.P.S.); the Department of Pediatrics, Section of Critical Care Medicine, University of Colorado School of Medicine and Children's Hospital Colorado, Aurora (A.B.M.); the Division of Pediatric Critical Care Medicine, Medical University of South Carolina, Charleston (E.H.M.); the Department of Pediatrics, Division of Cardiology, Louisiana State University Health Sciences Center and Children's Hospital of New Orleans, New Orleans (T.T.B.); the Division of Pediatric Infectious Diseases, Department of Pediatrics, Children's Mercy Kansas City, Kansas City, MO (J.E.S.); the Division of Critical Care Medicine, Department of Pediatrics, Akron Children's Hospital, Akron (R.A.N.), the Department of Pediatrics, University of Cincinnati College of Medicine, Cincinnati Children's Hospital Medical Center, Cincinnati (M.A.S.), and the Division of Pediatric Critical Care Medicine, Nationwide Children's Hospital Columbus, Columbus (K.E.B.) - all in Ohio; the Division of Critical Care Medicine, Department of Anesthesiology and Critical Care, Children's Hospital of Philadelphia, Philadelphia (K.C.); the Division of Pediatric Critical Care, Department of Pediatrics, Children's Hospital and Medical Center, Omaha, NE (M.L.C.); the Division of Pediatric Critical Care, Department of Pediatrics, Saint Barnabas Medical Center, Livingston, NJ (S.J.G.); the Divisions of Pediatric Infectious Diseases and Pediatric Critical Care Medicine, Department of Pediatric and Adolescent Medicine, Mayo Clinic, Rochester (E.R.L.), and the Division of Pediatric Critical Care, University of Minnesota Masonic Children's Hospital, Minneapolis (J.R.H.) - both in Minnesota; the Division of Pediatric Critical Care Medicine, Department of Pediatrics, University of Alabama at Birmingham, Birmingham (M.K.), the Division of Pediatric Infectious Diseases, Department of Pediatrics, UHealth/Holtz Children's Hospital, Miami (B.M.C.); the Ryan White Center for Pediatric Infectious Disease and Global Health, Department of Pediatrics, Indiana University School of Medicine, Indianapolis (S.S.B.); University of Arizona, Diamond Children's Banner Children's Medical Center, Tucson (M.G.G.); the Department of Pediatrics, Department of Microbiology, Division of Infectious Diseases, University of Mississippi Medical Center, Jackson (C.V.H.); the Department of Pediatrics, Children's Hospital of Michigan, Central Michigan University, Detroit (S.M.H.), and the Division of Pediatric Critical Care Medicine, Department of Pediatrics, Mott Children's Hospital and University of Michigan, Ann Arbor (H.R.F.); and the Division of Critical Care Medicine, Department of Pediatrics, Northwestern University Feinberg School of Medicine, Ann and Robert H. Lurie Children's Hospital of Chicago, Chicago (K.N.M.).; Campbell AP; From the Covid-19 Response Team, Centers for Disease Control and Prevention (S.M.O., A.M.P., L.D.Z., A.P.C., M.M.P.), and the Center for Childhood Infections and Vaccines of Children's Healthcare of Atlanta and the Department of Pediatrics, Emory University School of Medicine (S.K.) - both in Atlanta; the Department of Anesthesiology, Critical Care, and Pain Medicine, Boston Children's Hospital (M.M.N., A.G.R.), and the Departments of Anaesthesia and Pediatrics, Harvard Medical School (A.G.R.) - both in Boston; the Division of Pediatric Infectious Diseases, Department of Pediatrics, Vanderbilt University Medical Center, Nashville (N.B.H.); the Department of Pediatrics, Baylor College of Medicine, Immunization Project, Texas Children's Hospital, Houston (J.A.B., L.C.S.), and the Department of Pediatrics, Division of Critical Care Medicine, University of Texas Southwestern, Children's Medical Center Dallas, Dallas (M.M.); the Division of Infectious Diseases, Children's Hospital Los Angeles and Departments of Pediatrics and Molecular Microbiology and Immunology, University of Southern California, Los Angeles (P.S.P.), the Division of Pediatric Hospital Medicine, UC San Diego-Rady Children's Hospital, San Diego (M.A.C.), the Division of Critical Care Medicine, UCSF Benioff Children's Hospital Oakland (N.Z.C.), and the Department of Pediatrics, Divisions of Critical Care Medicine and Allergy, Immunology, and Bone Marrow Transplant, University of California, San Francisco, San Francisco (M.S.Z.) - all in California; Section of Pediatric Critical Care, Department of Pediatrics, Arkansas Children's Hospital, Little Rock (K.I.); the Department of Pediatrics, University of North Carolina at Chapel Hill Children's Hospital, Chapel Hill (T.C.W., S.P.S.); the Department of Pediatrics, Section of Critical Care Medicine, University of Colorado School of Medicine and Children's Hospital Colorado, Aurora (A.B.M.); the Division of Pediatric Critical Care Medicine, Medical University of South Carolina, Charleston (E.H.M.); the Department of Pediatrics, Division of Cardiology, Louisiana State University Health Sciences Center and Children's Hospital of New Orleans, New Orleans (T.T.B.); the Division of Pediatric Infectious Diseases, Department of Pediatrics, Children's Mercy Kansas City, Kansas City, MO (J.E.S.); the Division of Critical Care Medicine, Department of Pediatrics, Akron Children's Hospital, Akron (R.A.N.), the Department of Pediatrics, University of Cincinnati College of Medicine, Cincinnati Children's Hospital Medical Center, Cincinnati (M.A.S.), and the Division of Pediatric Critical Care Medicine, Nationwide Children's Hospital Columbus, Columbus (K.E.B.) - all in Ohio; the Division of Critical Care Medicine, Department of Anesthesiology and Critical Care, Children's Hospital of Philadelphia, Philadelphia (K.C.); the Division of Pediatric Critical Care, Department of Pediatrics, Children's Hospital and Medical Center, Omaha, NE (M.L.C.); the Division of Pediatric Critical Care, Department of Pediatrics, Saint Barnabas Medical Center, Livingston, NJ (S.J.G.); the Divisions of Pediatric Infectious Diseases and Pediatric Critical Care Medicine, Department of Pediatric and Adolescent Medicine, Mayo Clinic, Rochester (E.R.L.), and the Division of Pediatric Critical Care, University of Minnesota Masonic Children's Hospital, Minneapolis (J.R.H.) - both in Minnesota; the Division of Pediatric Critical Care Medicine, Department of Pediatrics, University of Alabama at Birmingham, Birmingham (M.K.), the Division of Pediatric Infectious Diseases, Department of Pediatrics, UHealth/Holtz Children's Hospital, Miami (B.M.C.); the Ryan White Center for Pediatric Infectious Disease and Global Health, Department of Pediatrics, Indiana University School of Medicine, Indianapolis (S.S.B.); University of Arizona, Diamond Children's Banner Children's Medical Center, Tucson (M.G.G.); the Department of Pediatrics, Department of Microbiology, Division of Infectious Diseases, University of Mississippi Medical Center, Jackson (C.V.H.); the Department of Pediatrics, Children's Hospital of Michigan, Central Michigan University, Detroit (S.M.H.), and the Division of Pediatric Critical Care Medicine, Department of Pediatrics, Mott Children's Hospital and University of Michigan, Ann Arbor (H.R.F.); and the Division of Critical Care Medicine, Department of Pediatrics, Northwestern University Feinberg School of Medicine, Ann and Robert H. Lurie Children's Hospital of Chicago, Chicago (K.N.M.).; Patel MM; From the Covid-19 Response Team, Centers for Disease Control and Prevention (S.M.O., A.M.P., L.D.Z., A.P.C., M.M.P.), and the Center for Childhood Infections and Vaccines of Children's Healthcare of Atlanta and the Department of Pediatrics, Emory University School of Medicine (S.K.) - both in Atlanta; the Department of Anesthesiology, Critical Care, and Pain Medicine, Boston Children's Hospital (M.M.N., A.G.R.), and the Departments of Anaesthesia and Pediatrics, Harvard Medical School (A.G.R.) - both in Boston; the Division of Pediatric Infectious Diseases, Department of Pediatrics, Vanderbilt University Medical Center, Nashville (N.B.H.); the Department of Pediatrics, Baylor College of Medicine, Immunization Project, Texas Children's Hospital, Houston (J.A.B., L.C.S.), and the Department of Pediatrics, Division of Critical Care Medicine, University of Texas Southwestern, Children's Medical Center Dallas, Dallas (M.M.); the Division of Infectious Diseases, Children's Hospital Los Angeles and Departments of Pediatrics and Molecular Microbiology and Immunology, University of Southern California, Los Angeles (P.S.P.), the Division of Pediatric Hospital Medicine, UC San Diego-Rady Children's Hospital, San Diego (M.A.C.), the Division of Critical Care Medicine, UCSF Benioff Children's Hospital Oakland (N.Z.C.), and the Department of Pediatrics, Divisions of Critical Care Medicine and Allergy, Immunology, and Bone Marrow Transplant, University of California, San Francisco, San Francisco (M.S.Z.) - all in California; Section of Pediatric Critical Care, Department of Pediatrics, Arkansas Children's Hospital, Little Rock (K.I.); the Department of Pediatrics, University of North Carolina at Chapel Hill Children's Hospital, Chapel Hill (T.C.W., S.P.S.); the Department of Pediatrics, Section of Critical Care Medicine, University of Colorado School of Medicine and Children's Hospital Colorado, Aurora (A.B.M.); the Division of Pediatric Critical Care Medicine, Medical University of South Carolina, Charleston (E.H.M.); the Department of Pediatrics, Division of Cardiology, Louisiana State University Health Sciences Center and Children's Hospital of New Orleans, New Orleans (T.T.B.); the Division of Pediatric Infectious Diseases, Department of Pediatrics, Children's Mercy Kansas City, Kansas City, MO (J.E.S.); the Division of Critical Care Medicine, Department of Pediatrics, Akron Children's Hospital, Akron (R.A.N.), the Department of Pediatrics, University of Cincinnati College of Medicine, Cincinnati Children's Hospital Medical Center, Cincinnati (M.A.S.), and the Division of Pediatric Critical Care Medicine, Nationwide Children's Hospital Columbus, Columbus (K.E.B.) - all in Ohio; the Division of Critical Care Medicine, Department of Anesthesiology and Critical Care, Children's Hospital of Philadelphia, Philadelphia (K.C.); the Division of Pediatric Critical Care, Department of Pediatrics, Children's Hospital and Medical Center, Omaha, NE (M.L.C.); the Division of Pediatric Critical Care, Department of Pediatrics, Saint Barnabas Medical Center, Livingston, NJ (S.J.G.); the Divisions of Pediatric Infectious Diseases and Pediatric Critical Care Medicine, Department of Pediatric and Adolescent Medicine, Mayo Clinic, Rochester (E.R.L.), and the Division of Pediatric Critical Care, University of Minnesota Masonic Children's Hospital, Minneapolis (J.R.H.) - both in Minnesota; the Division of Pediatric Critical Care Medicine, Department of Pediatrics, University of Alabama at Birmingham, Birmingham (M.K.), the Division of Pediatric Infectious Diseases, Department of Pediatrics, UHealth/Holtz Children's Hospital, Miami (B.M.C.); the Ryan White Center for Pediatric Infectious Disease and Global Health, Department of Pediatrics, Indiana University School of Medicine, Indianapolis (S.S.B.); University of Arizona, Diamond Children's Banner Children's Medical Center, Tucson (M.G.G.); the Department of Pediatrics, Department of Microbiology, Division of Infectious Diseases, University of Mississippi Medical Center, Jackson (C.V.H.); the Department of Pediatrics, Children's Hospital of Michigan, Central Michigan University, Detroit (S.M.H.), and the Division of Pediatric Critical Care Medicine, Department of Pediatrics, Mott Children's Hospital and University of Michigan, Ann Arbor (H.R.F.); and the Division of Critical Care Medicine, Department of Pediatrics, Northwestern University Feinberg School of Medicine, Ann and Robert H. Lurie Children's Hospital of Chicago, Chicago (K.N.M.).; Randolph AG; From the Covid-19 Response Team, Centers for Disease Control and Prevention (S.M.O., A.M.P., L.D.Z., A.P.C., M.M.P.), and the Center for Childhood Infections and Vaccines of Children's Healthcare of Atlanta and the Department of Pediatrics, Emory University School of Medicine (S.K.) - both in Atlanta; the Department of Anesthesiology, Critical Care, and Pain Medicine, Boston Children's Hospital (M.M.N., A.G.R.), and the Departments of Anaesthesia and Pediatrics, Harvard Medical School (A.G.R.) - both in Boston; the Division of Pediatric Infectious Diseases, Department of Pediatrics, Vanderbilt University Medical Center, Nashville (N.B.H.); the Department of Pediatrics, Baylor College of Medicine, Immunization Project, Texas Children's Hospital, Houston (J.A.B., L.C.S.), and the Department of Pediatrics, Division of Critical Care Medicine, University of Texas Southwestern, Children's Medical Center Dallas, Dallas (M.M.); the Division of Infectious Diseases, Children's Hospital Los Angeles and Departments of Pediatrics and Molecular Microbiology and Immunology, University of Southern California, Los Angeles (P.S.P.), the Division of Pediatric Hospital Medicine, UC San Diego-Rady Children's Hospital, San Diego (M.A.C.), the Division of Critical Care Medicine, UCSF Benioff Children's Hospital Oakland (N.Z.C.), and the Department of Pediatrics, Divisions of Critical Care Medicine and Allergy, Immunology, and Bone Marrow Transplant, University of California, San Francisco, San Francisco (M.S.Z.) - all in California; Section of Pediatric Critical Care, Department of Pediatrics, Arkansas Children's Hospital, Little Rock (K.I.); the Department of Pediatrics, University of North Carolina at Chapel Hill Children's Hospital, Chapel Hill (T.C.W., S.P.S.); the Department of Pediatrics, Section of Critical Care Medicine, University of Colorado School of Medicine and Children's Hospital Colorado, Aurora (A.B.M.); the Division of Pediatric Critical Care Medicine, Medical University of South Carolina, Charleston (E.H.M.); the Department of Pediatrics, Division of Cardiology, Louisiana State University Health Sciences Center and Children's Hospital of New Orleans, New Orleans (T.T.B.); the Division of Pediatric Infectious Diseases, Department of Pediatrics, Children's Mercy Kansas City, Kansas City, MO (J.E.S.); the Division of Critical Care Medicine, Department of Pediatrics, Akron Children's Hospital, Akron (R.A.N.), the Department of Pediatrics, University of Cincinnati College of Medicine, Cincinnati Children's Hospital Medical Center, Cincinnati (M.A.S.), and the Division of Pediatric Critical Care Medicine, Nationwide Children's Hospital Columbus, Columbus (K.E.B.) - all in Ohio; the Division of Critical Care Medicine, Department of Anesthesiology and Critical Care, Children's Hospital of Philadelphia, Philadelphia (K.C.); the Division of Pediatric Critical Care, Department of Pediatrics, Children's Hospital and Medical Center, Omaha, NE (M.L.C.); the Division of Pediatric Critical Care, Department of Pediatrics, Saint Barnabas Medical Center, Livingston, NJ (S.J.G.); the Divisions of Pediatric Infectious Diseases and Pediatric Critical Care Medicine, Department of Pediatric and Adolescent Medicine, Mayo Clinic, Rochester (E.R.L.), and the Division of Pediatric Critical Care, University of Minnesota Masonic Children's Hospital, Minneapolis (J.R.H.) - both in Minnesota; the Division of Pediatric Critical Care Medicine, Department of Pediatrics, University of Alabama at Birmingham, Birmingham (M.K.), the Division of Pediatric Infectious Diseases, Department of Pediatrics, UHealth/Holtz Children's Hospital, Miami (B.M.C.); the Ryan White Center for Pediatric Infectious Disease and Global Health, Department of Pediatrics, Indiana University School of Medicine, Indianapolis (S.S.B.); University of Arizona, Diamond Children's Banner Children's Medical Center, Tucson (M.G.G.); the Department of Pediatrics, Department of Microbiology, Division of Infectious Diseases, University of Mississippi Medical Center, Jackson (C.V.H.); the Department of Pediatrics, Children's Hospital of Michigan, Central Michigan University, Detroit (S.M.H.), and the Division of Pediatric Critical Care Medicine, Department of Pediatrics, Mott Children's Hospital and University of Michigan, Ann Arbor (H.R.F.); and the Division of Critical Care Medicine, Department of Pediatrics, Northwestern University Feinberg School of Medicine, Ann and Robert H. Lurie Children's Hospital of Chicago, Chicago (K.N.M.).

Publisher: Massachusetts Medical Society Country of Publication: United States NLM ID: 0255562 Publication Model: Print-Electronic Cited Medium: Internet ISSN: 1533-4406 (Electronic) Linking ISSN: 00284793 NLM ISO Abbreviation: N Engl J Med Subsets: MEDLINE

Bline AP; Social Science Environmental Health Research Institute, Northeastern University, Boston, MA, 02115, USA. a.bline@northeastern.edu.; Silent Spring Institute, Newton, MA, 02460, USA. a.bline@northeastern.edu.; DeWitt JC; Department of Environmental & Molecular Toxicology, Oregon State University, Corvallis, OR, 97331, USA.; Kwiatkowski CF; Department of Biological Sciences, North Carolina State University, Raleigh, NC, 27695, USA.; Pelch KE; Natural Resources Defense Council, San Francisco, CA, 94104, USA.; Reade A; Natural Resources Defense Council, San Francisco, CA, 94104, USA.; Varshavsky JR; Departments of Health Sciences and Civil and Environmental Engineering, Northeastern University, Boston, MA, 02115, USA.

Publisher: Springer International Publishing AG Country of Publication: Switzerland NLM ID: 101629387 Publication Model: Print-Electronic Cited Medium: Internet ISSN: 2196-5412 (Electronic) Linking ISSN: 21965412 NLM ISO Abbreviation: Curr Environ Health Rep Subsets: MEDLINE

Bline AP; Social Science Environmental Health Research Institute, Northeastern University, Boston, MA, United States; Silent Spring Institute, Newton, MA, United States. Electronic address: a.bline@northeastern.edu.; Ellis LB; Social Science Environmental Health Research Institute, Northeastern University, Boston, MA, United States; Department of Health Sciences, Northeastern University, Boston, MA, United States. Electronic address: ellis.la@northeastern.edu.; Pelch KE; Natural Resources Defense Council, San Francisco, CA, United States. Electronic address: kpelch@nrdc.org.; Lam J; Department of Public Health, California State University, East Bay, Hayward, CA, United States. Electronic address: juleen.lam@csueastbay.edu.; Sen S; College of Medicine, The University of Tennessee Health Science Center, Memphis, TN, United States. Electronic address: sen@uthsc.edu.; Zlatnik M; Department of Obstetrics, Gynecology and Reproductive Sciences, Program on Reproductive Health and the Environment, University of California San Francisco, San Francisco, CA, United States. Electronic address: marya.zlatnik@ucsf.edu.; Varshavsky J; Social Science Environmental Health Research Institute, Northeastern University, Boston, MA, United States; Department of Health Sciences, Northeastern University, Boston, MA, United States; Department of Civil and Environmental Engineering, Northeastern University, Boston, MA, United States. Electronic address: j.varshavsky@northeastern.edu.

Publisher: Elsevier Science Country of Publication: Netherlands NLM ID: 7807270 Publication Model: Print-Electronic Cited Medium: Internet ISSN: 1873-6750 (Electronic) Linking ISSN: 01604120 NLM ISO Abbreviation: Environ Int Subsets: MEDLINE

Siders JL; School of Science, Technology, and Mathematics, Ohio Northern University, Ada, OH USA.; Bieser KL; Department of Physical and Life Sciences, Nevada State College, Henderson, NV USA.; Hamill DR; Department of Zoology, Ohio Wesleyan University, Delaware, OH USA.; Acosta EC; Department of Physical and Life Sciences, Nevada State College, Henderson, NV USA.; Alexander OK; School of Science, Technology, and Mathematics, Ohio Northern University, Ada, OH USA.; Ali HI; Biology Department, University of Detroit Mercy, Detroit, MI USA.; Anderson MJ; School of Science, Technology, and Mathematics, Ohio Northern University, Ada, OH USA.; Arrasmith HR; School of Science, Technology, and Mathematics, Ohio Northern University, Ada, OH USA.; Azam M; Biology Department, University of Detroit Mercy, Detroit, MI USA.; Beeman NJ; Department of Physical and Life Sciences, Nevada State College, Henderson, NV USA.; Beydoun H; Biology Department, University of Detroit Mercy, Detroit, MI USA.; Bishop LJ; School of Science, Technology, and Mathematics, Ohio Northern University, Ada, OH USA.; Blair MD; School of Science, Technology, and Mathematics, Ohio Northern University, Ada, OH USA.; Bletch B; Biology Department, University of Detroit Mercy, Detroit, MI USA.; Bline HR; School of Science, Technology, and Mathematics, Ohio Northern University, Ada, OH USA.; Brown JC; School of Science, Technology, and Mathematics, Ohio Northern University, Ada, OH USA.; Burns KM; School of Science, Technology, and Mathematics, Ohio Northern University, Ada, OH USA.; Calagua KC; Department of Physical and Life Sciences, Nevada State College, Henderson, NV USA.; Chafin L; Department of Zoology, Ohio Wesleyan University, Delaware, OH USA.; Christy WA; Department of Zoology, Ohio Wesleyan University, Delaware, OH USA.; Ciamacco C; School of Science, Technology, and Mathematics, Ohio Northern University, Ada, OH USA.; Cizauskas H; Biology Department, University of Detroit Mercy, Detroit, MI USA.; Colwell CM; Department of Zoology, Ohio Wesleyan University, Delaware, OH USA.; Courtright AR; Department of Zoology, Ohio Wesleyan University, Delaware, OH USA.; Diaz Alavez L; Department of Physical and Life Sciences, Nevada State College, Henderson, NV USA.; Ecret RI; Department of Physical and Life Sciences, Nevada State College, Henderson, NV USA.; Edriss F; Biology Department, University of Detroit Mercy, Detroit, MI USA.; Ellerbrock TG; School of Science, Technology, and Mathematics, Ohio Northern University, Ada, OH USA.; Ellis MM; School of Science, Technology, and Mathematics, Ohio Northern University, Ada, OH USA.; Extine EM; School of Science, Technology, and Mathematics, Ohio Northern University, Ada, OH USA.; Feldman E; Department of Physical and Life Sciences, Nevada State College, Henderson, NV USA.; Fickenworth LJ; School of Science, Technology, and Mathematics, Ohio Northern University, Ada, OH USA.; Goeller CM; School of Science, Technology, and Mathematics, Ohio Northern University, Ada, OH USA.; Grogg AS; School of Science, Technology, and Mathematics, Ohio Northern University, Ada, OH USA.; Hernandez Y; Department of Physical and Life Sciences, Nevada State College, Henderson, NV USA.; Hershner A; School of Science, Technology, and Mathematics, Ohio Northern University, Ada, OH USA.; Jauss MM; School of Science, Technology, and Mathematics, Ohio Northern University, Ada, OH USA.; Jimenez Garcia L; School of Science, Technology, and Mathematics, Ohio Northern University, Ada, OH USA.; Franks KE; School of Science, Technology, and Mathematics, Ohio Northern University, Ada, OH USA.; Kazubski ET; School of Science, Technology, and Mathematics, Ohio Northern University, Ada, OH USA.; Landis ER; School of Science, Technology, and Mathematics, Ohio Northern University, Ada, OH USA.; Langub J; Department of Physical and Life Sciences, Nevada State College, Henderson, NV USA.; Lassek TN; Department of Physical and Life Sciences, Nevada State College, Henderson, NV USA.; Le TC; School of Science, Technology, and Mathematics, Ohio Northern University, Ada, OH USA.; Lee JM; School of Science, Technology, and Mathematics, Ohio Northern University, Ada, OH USA.; Levine DP; Department of Physical and Life Sciences, Nevada State College, Henderson, NV USA.; Lightfoot PJ; Department of Zoology, Ohio Wesleyan University, Delaware, OH USA.; Love N; Department of Physical and Life Sciences, Nevada State College, Henderson, NV USA.; Maalhagh-Fard A; Biology Department, University of Detroit Mercy, Detroit, MI USA.; Maguire C; School of Science, Technology, and Mathematics, Ohio Northern University, Ada, OH USA.; McGinnis BE; Department of Physical and Life Sciences, Nevada State College, Henderson, NV USA.; Mehta BV; School of Science, Technology, and Mathematics, Ohio Northern University, Ada, OH USA.; Melendrez V; Department of Physical and Life Sciences, Nevada State College, Henderson, NV USA.; Mena ZE; Department of Physical and Life Sciences, Nevada State College, Henderson, NV USA.; Mendell S; Biology Department, University of Detroit Mercy, Detroit, MI USA.; Montiel-Garcia P; Department of Physical and Life Sciences, Nevada State College, Henderson, NV USA.; Murry AS; Biology Department, University of Detroit Mercy, Detroit, MI USA.; ReBUILDetroit, University of Detroit Mercy, Detroit, MI USA.; Newland RA; School of Science, Technology, and Mathematics, Ohio Northern University, Ada, OH USA.; Nobles RM; Department of Physical and Life Sciences, Nevada State College, Henderson, NV USA.; Patel N; Department of Physical and Life Sciences, Nevada State College, Henderson, NV USA.; Patil Y; Biology Department, University of Detroit Mercy, Detroit, MI USA.; Pfister CL; School of Science, Technology, and Mathematics, Ohio Northern University, Ada, OH USA.; Ramage V; School of Science, Technology, and Mathematics, Ohio Northern University, Ada, OH USA.; Ray MR; School of Science, Technology, and Mathematics, Ohio Northern University, Ada, OH USA.; Rodrigues J; Department of Physical and Life Sciences, Nevada State College, Henderson, NV USA.; Rodriquez VC; Department of Physical and Life Sciences, Nevada State College, Henderson, NV USA.; Romero Y; Department of Physical and Life Sciences, Nevada State College, Henderson, NV USA.; Scott AM; School of Science, Technology, and Mathematics, Ohio Northern University, Ada, OH USA.; Shaba N; Biology Department, University of Detroit Mercy, Detroit, MI USA.; Sieg S; Biology Department, University of Detroit Mercy, Detroit, MI USA.; Silva K; School of Science, Technology, and Mathematics, Ohio Northern University, Ada, OH USA.; Singh S; Biology Department, University of Detroit Mercy, Detroit, MI USA.; Spargo AJ; School of Science, Technology, and Mathematics, Ohio Northern University, Ada, OH USA.; Spitnale SJ; School of Science, Technology, and Mathematics, Ohio Northern University, Ada, OH USA.; Sweeden N; Department of Physical and Life Sciences, Nevada State College, Henderson, NV USA.; Tague L; Biology Department, University of Detroit Mercy, Detroit, MI USA.; Tavernini BM; Department of Physical and Life Sciences, Nevada State College, Henderson, NV USA.; Tran K; School of Science, Technology, and Mathematics, Ohio Northern University, Ada, OH USA.; Tungol L; Biology Department, University of Detroit Mercy, Detroit, MI USA.; Vestal KA; School of Science, Technology, and Mathematics, Ohio Northern University, Ada, OH USA.; Wetherbee A; School of Science, Technology, and Mathematics, Ohio Northern University, Ada, OH USA.; Wright KM; School of Science, Technology, and Mathematics, Ohio Northern University, Ada, OH USA.; Yeager AT; School of Science, Technology, and Mathematics, Ohio Northern University, Ada, OH USA.; Zahid R; Biology Department, University of Detroit Mercy, Detroit, MI USA.; Kagey JD; Biology Department, University of Detroit Mercy, Detroit, MI USA.

Publisher: Caltech Library Country of Publication: United States NLM ID: 101759238 Publication Model: Electronic Cited Medium: Internet ISSN: 2578-9430 (Electronic) Linking ISSN: 25789430 NLM ISO Abbreviation: MicroPubl Biol Subsets: PubMed not MEDLINE

Stanek TJ; Department of Genetics, Human Genetics Institute of New Jersey, Rutgers University, Piscataway, NJ, USA.; Leung W; Department of Biology, Washington University in St. Louis, St. Louis, MO, USA.; Shaffer CD; Department of Biology, Washington University in St. Louis, St. Louis, MO, USA.; Olaveja I; Department of Biology, New Jersey City University, Jersey City, NJ, USA.; Laughlin A; Department of Biology, Washington University in St. Louis, St. Louis, MO, USA.; Department of Biology, New Jersey City University, Jersey City, NJ, USA.; Hester J; Department of Genetics, Human Genetics Institute of New Jersey, Rutgers University, Piscataway, NJ, USA.; Department of Biology, New Jersey City University, Jersey City, NJ, USA.; Garrido D; Department of Biology, New Jersey City University, Jersey City, NJ, USA.; Oh EK; Department of Biology, Washington University in St. Louis, St. Louis, MO, USA.; Department of Biology, New Jersey City University, Jersey City, NJ, USA.; Volski M; Department of Genetics, Human Genetics Institute of New Jersey, Rutgers University, Piscataway, NJ, USA.; Department of Biology, New Jersey City University, Jersey City, NJ, USA.; Panda N; Department of Biology, Washington University in St. Louis, St. Louis, MO, USA.; Department of Biology, New Jersey City University, Jersey City, NJ, USA.; Mo M; Department of Biology, Washington University in St. Louis, St. Louis, MO, USA.; Department of Biology, New Jersey City University, Jersey City, NJ, USA.; Cordes E; Department of Biology, Washington University in St. Louis, St. Louis, MO, USA.; Dalling M; Department of Biology, Washington University in St. Louis, St. Louis, MO, USA.; Department of Biology, New Jersey City University, Jersey City, NJ, USA.; Kershaw K; Department of Biology, New Jersey City University, Jersey City, NJ, USA.; Department of Biology, Saint Joseph's University, Philadelphia, PA, USA.; Arnott M; Department of Biology, New Jersey City University, Jersey City, NJ, USA.; Department of Biology, Lewis & Clark College, Portland, OR, USA.; Daly S; Department of Biology, Washington University in St. Louis, St. Louis, MO, USA.; Department of Biology, New Jersey City University, Jersey City, NJ, USA.; Valenzuela SG; Department of Biology, New Jersey City University, Jersey City, NJ, USA.; Thompson P; Department of Genetics, Human Genetics Institute of New Jersey, Rutgers University, Piscataway, NJ, USA.; Department of Biology, New Jersey City University, Jersey City, NJ, USA.; Hastert KL; Department of Biology, New Jersey City University, Jersey City, NJ, USA.; Sabb D; Department of Biology, New Jersey City University, Jersey City, NJ, USA.; Karpinski K; Department of Biology, New Jersey City University, Jersey City, NJ, USA.; Department of Biology, Saint Joseph's University, Philadelphia, PA, USA.; Arora MN; Department of Biology, Washington University in St. Louis, St. Louis, MO, USA.; Rius N; Department of Biology, New Jersey City University, Jersey City, NJ, USA.; LoBello L; Department of Biology, Washington University in St. Louis, St. Louis, MO, USA.; Department of Biology, New Jersey City University, Jersey City, NJ, USA.; Jaramillo S; Department of Biology, New Jersey City University, Jersey City, NJ, USA.; Sonavane O; Department of Genetics, Human Genetics Institute of New Jersey, Rutgers University, Piscataway, NJ, USA.; Department of Biology, New Jersey City University, Jersey City, NJ, USA.; Herrmann A; Department of Biology, Washington University in St. Louis, St. Louis, MO, USA.; Department of Biology, New Jersey City University, Jersey City, NJ, USA.; Reed LK; Department of Biological Sciences, The University of Alabama, Tuscaloosa, AL, USA.; Elgin SCR; Department of Biology, Washington University in St. Louis, St. Louis, MO, USA.; Arrigo C; Department of Biology, New Jersey City University, Jersey City, NJ, USA.; Ellison CE; Department of Genetics, Human Genetics Institute of New Jersey, Rutgers University, Piscataway, NJ, USA.

Publisher: Oxford University Press Country of Publication: United States NLM ID: 8501455 Publication Model: Print Cited Medium: Internet ISSN: 1537-1719 (Electronic) Linking ISSN: 07374038 NLM ISO Abbreviation: Mol Biol Evol Subsets: MEDLINE