Abstract
BBV152 is a whole-virion inactivated vaccine based on the Asp614Gly variant. BBV152 is the first alum-imidazoquinolin-adjuvanted vaccine authorized for use in large populations. Here we characterized the magnitude, quality and persistence of cellular and humoral memory responses up to 6 months post vaccination. We report that the magnitude of vaccine-induced spike and nucleoprotein antibodies was comparable with that produced after infection. Receptor binding domain-specific antibodies declined against variants in the order of Alpha (B.1.1.7; 3-fold), Delta (B.1.617.2; 7-fold) and Beta (B.1.351; 10-fold). However, pseudovirus neutralizing antibodies declined up to 2-fold against the Delta followed by the Beta variant (1.7-fold). Vaccine-induced memory B cells were also affected by the Delta and Beta variants. The SARS-CoV-2-specific multicytokine-expressing CD4+ T cells were found in ~85% of vaccinated individuals. Only a ~1.3-fold reduction in efficacy was observed in CD4+ T cells against the Beta variant. We found that antigen-specific CD4+ T cells were present in the central memory compartment and persisted for at least up to 6 months post vaccination. Vaccine-induced CD8+ T cells were detected in ~50% of individuals. Importantly, the vaccine was capable of inducing follicular T helper cells that exhibited B-cell help potential. These findings show that inactivated vaccine BBV152 induces robust immune memory to SARS-CoV-2 and variants of concern that persists for at least 6 months after vaccination.
【초록키워드】 SARS-CoV-2, Efficacy, Vaccine, vaccination, antibody, variant, Infection, variants of concern, Delta, variants, Inactivated vaccine, persistence, Beta, immune memory, CD8+ T cell, CD4+ T cell, memory B cell, binding, B-cell, memory response, cellular, humoral, T helper cell, help, vaccinated individuals, post vaccination, pseudovirus neutralizing antibody, populations, robust, produced, affected, exhibited, characterized, magnitude, induce, comparable, individuals, the vaccine, reduction in, declined, central memory, follicular, persist, 【제목키워드】 SARS-CoV-2, Vaccine, variants of concern, immune memory, cellular, robust, elicit,