부산대학교 도서관

India is one of the most affected countries by COVID-19 pandemic; but little is understood regarding immune responses to SARS-CoV-2 in this region. Herein we examined SARS-CoV-2 neutralizing antibodies, IgG, IgM, IgA and memory B cells in COVID-19 recovered individual from India. While a vast majority of COVID-19 recovered individuals showed SARS-CoV-2 RBD-specific IgG, IgA and IgM antibodies (38/42, 90.47%; 21/42, 50%; 33/42, 78.57% respectively), only half of them had appreciable neutralizing antibody titers. RBD-specific IgG, but not IgA or IgM titers, correlated with neutralizing antibody titers and RBD-specific memory B cell frequencies. These findings have timely significance for identifying potential donors for plasma therapy using RBD-specific IgG assays as surrogate measurement for neutralizing antibodies in India. Further, this study provides useful information needed for designing large-scale studies towards understanding of inter-individual variation in immune memory to SARS CoV-2 natural infection for future vaccine evaluation and implementation efforts. • This study characterized neutralizing/ binding antibodies and memory B cells in COVID-19 recovered individuals from India. • We show that half of the COVID-19 recovered individuals generated readily detectable SARS COV-2 neutralizing antibodies. • SARS COV-2 RBD specific IgG titers provide a surrogate measure for neutralizing titers and memory B cell frequencies. • These findings aid selection of suitable donors for plasma therapy against COVID-19. • Our findings have implications to understand generation and maintenance of SARS Cov-2 protective immunity and vaccines. [ABSTRACT FROM AUTHOR]