학술논문
Robust humoral and cellular recall responses to AZD1222 attenuate breakthrough SARS-CoV-2 infection compared to unvaccinated
Document Type
article
Author
Jill Maaske; Stephanie Sproule; Ann R. Falsey; Magdalena E. Sobieszczyk; Anne F. Luetkemeyer; Grant C. Paulsen; Sharon A. Riddler; Merlin L. Robb; Charlotte-Paige Rolle; Beverly E. Sha; Tina Tong; Bahar Ahani; Anastasia A. Aksyuk; Himanshu Bansal; Timothy Egan; Brett Jepson; Marcelino Padilla; Nirmeshkumar Patel; Kathryn Shoemaker; Ann Marie Stanley; Phillip A. Swanson; Deidre Wilkins; Tonya Villafana; Justin A. Green; Elizabeth J. Kelly
Source
Frontiers in Immunology, Vol 13 (2023)
Subject
Language
English
ISSN
1664-3224
Abstract
BackgroundBreakthrough severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection in coronavirus disease 2019 (COVID-19) vaccinees typically produces milder disease than infection in unvaccinated individuals.MethodsTo explore disease attenuation, we examined COVID-19 symptom burden and immuno-virologic responses to symptomatic SARS-CoV-2 infection in participants (AZD1222: n=177/17,617; placebo: n=203/8,528) from a 2:1 randomized, placebo-controlled, phase 3 study of two-dose primary series AZD1222 (ChAdOx1 nCoV-19) vaccination (NCT04516746).ResultsWe observed that AZD1222 vaccinees had an overall lower incidence and shorter duration of COVID-19 symptoms compared with placebo recipients, as well as lower SARS-CoV-2 viral loads and a shorter median duration of viral shedding in saliva. Vaccinees demonstrated a robust antibody recall response versus placebo recipients with low-to-moderate inverse correlations with virologic endpoints. Vaccinees also demonstrated an enriched polyfunctional spike-specific Th-1-biased CD4+ and CD8+ T-cell response that was associated with strong inverse correlations with virologic endpoints.ConclusionRobust immune responses following AZD1222 vaccination attenuate COVID-19 disease severity and restrict SARS-CoV-2 transmission potential by reducing viral loads and the duration of viral shedding in saliva. Collectively, these analyses underscore the essential role of vaccination in mitigating the COVID-19 pandemic.