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.

BBV152 是一种基于 Asp614Gly 变体的全病毒粒子灭活疫苗。BBV152 是第一个获准用于大量人群的明矾-咪唑喹啉佐剂疫苗。在这里，我们描述了疫苗接种后长达 6 个月的细胞和体液记忆反应的幅度、质量和持久性。我们报告疫苗诱导的尖峰和核蛋白抗体的量级与感染后产生的量级相当。受体结合域特异性抗体针对变体按 Alpha（B.1.1.7；3 倍）、Delta（B.1.617.2；7 倍）和 Beta（B.1.351；10 倍）的顺序下降。然而，针对 Delta 的假病毒中和抗体下降了 2 倍，其次是 Beta 变体（1.7 倍）。疫苗诱导的记忆 B 细胞也受到 Delta 和 Beta 变体的影响。⁺ T 细胞在约 85% 的接种疫苗的个体中发现。^{在 CD4 +} T 细胞中仅观察到针对 Beta 变体的功效降低了约 1.3 倍。我们发现抗原特异性 CD4 ⁺ T 细胞存在于中央记忆隔室中，并且在疫苗接种后至少持续长达 6 个月。在约 50% 的个体中检测到疫苗诱导的 CD8 ^{+ T 细胞。}重要的是，该疫苗能够诱导表现出 B 细胞帮助潜力的滤泡 T 辅助细胞。这些发现表明，灭活疫苗 BBV152 可诱导对 SARS-CoV-2 和相关变异体的强大免疫记忆，并在接种疫苗后至少持续 6 个月。