Comparison of antibody and T cell responses elicited by BBIBP-CorV (Sinopharm) and BNT162b2 (Pfizer-BioNTech) vaccines against SARS-CoV-2 in healthy adult humans

Abstract

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.

The immunogenicity and reactogenicity of four COVID-19 booster vaccinations against SARS-CoV-2 variants of concerns (Delta, Beta, and Omicron) following CoronaVac or ChAdOx1 nCoV-19 primary series

“…We found BBIBP-CorV boosting poorly induced IGRA response; however, it is important to note that inactivated vaccine (i.e. BBIBP-CorV) may have other antigens (i.e., M or N proteins) that induce T cell responses [36], whereas in our study, we only examined T cell responses to S protein, and thus may have underestimated the cellular responses. The low T cell boosting responses following homologous boosting regimen of ChAdOx1 is in line with the low neutralizing antibody boosting responses observed in this study.…”

RBD-specific antibody responses after two doses of BBIBP-CorV (Sinopharm, Beijing CNBG) vaccine

“…Fu performed an extensive analysis on a small number of patients [ 47 ] but did not report data by age, and all subject was below 60. The antibody and T cell response study of Vályi-Nagy et al was carried out in Hungary just as ours [ 48 ], but unfortunately included almost no elderly subjects. This study, however, did find cellular response even with the Sinopharm vaccine.…”

Severe acute respiratory syndrome coronavirus 2 vaccines – a review of adverse effects and safety profiles

“…Therefore the authors concluded that both vaccines were capable of eliciting T cell responses but the Pfizer vaccine elicited a stronger but narrower response. 27 These findings of T cell responses by the Sinopharm vaccine were further confirmed in another study. 28 In a study assessing T cell responses in the two mRNA vaccines (Pfizer and Moderna), it was found that both the vaccines showed broad T cell responses to the SARS CoV-2 spike protein which were able to effectively recognize variants of the SARS CoV-2 virus as well as the ancestral virus, providing cross-protection.…”