In the present study, humoral and T cell-mediated immune responses elicited by BBIBP-CorV (inactivated virus) and BNT162b2 (mRNA-based) vaccines against SARS-CoV-2 virus were compared. Convalescent volunteers were also investigated to evaluate adaptive immunity induced by live virus. Although both vaccines induced antibody- and T cell-mediated immune responses, our analysis revealed significant quantitative and qualitative differences between the two types of challenges. The BBIBP-CorV vaccine elicited antireceptor-binding domain (RBD) IgG, as well as anti-spike protein (S) IgG and IgA antibodies in healthy individuals, the levels of which were much lower than after BNT162b2 vaccination but still higher than in the convalescent patients. The cumulative IFNγ-positive T cell response, however, was only twofold higher in participants injected with BNT162b2 compared to those who were primed and boosted with BBIBP-CorV vaccine. Moreover, the inactivated virus vaccine induced T cell response that targets not only the S but also the nucleocapsid (N) and membrane (M) proteins, whereas the mRNA vaccine was able to elicit a much narrower response that targets the S protein epitopes only. Thus, the pattern of BBIBP-CorV-induced T cell response in virus-naive participants was similar to the cell-mediated anti-SARS-CoV-2 response observed in convalescent patients. Based on these data, we can conclude that the BBIBP-CorV inactivated virus vaccine is immunologically effective. However, the duration of BBIBP-CorV-induced integrated, antibody, and T cell-mediated, immune responses needs further investigation.

在本研究中，比较了 BBIBP-CorV（灭活病毒）和 BNT162b2（基于 mRNA）疫苗针对 SARS-CoV-2 病毒引发的体液和 T 细胞介导的免疫反应。还对恢复期志愿者进行了调查，以评估由活病毒诱导的适应性免疫。尽管两种疫苗都诱导了抗体和 T 细胞介导的免疫反应，但我们的分析揭示了这两种挑战之间存在显着的定量和定性差异。BBIBP-CorV 疫苗在健康个体中引发抗受体结合域 (RBD) IgG，以及抗刺突蛋白 (S) IgG 和 IgA 抗体，其水平远低于 BNT162b2 疫苗接种后，但仍高于康复期患者。然而，累积的 IFNγ 阳性 T 细胞反应，与接受 BBIBP-CorV 疫苗初免和加强的参与者相比，注射 BNT162b2 的参与者仅高出两倍。此外，灭活病毒疫苗诱导的 T 细胞反应不仅针对 S，而且针对核衣壳 (N) 和膜 (M) 蛋白，而 mRNA 疫苗能够引发仅针对 S 蛋白表位的更窄的反应。因此，在未感染病毒的参与者中，BBIBP-CorV 诱导的 T 细胞反应模式与在恢复期患者中观察到的细胞介导的抗 SARS-CoV-2 反应相似。基于这些数据，我们可以得出结论，BBIBP-CorV灭活病毒疫苗在免疫学上是有效的。然而，BBIBP-CorV 诱导的整合、抗体和 T 细胞介导的免疫反应的持续时间需要进一步研究。