Comparison of antibody immune responses between BNT162b2 and mRNA-1273 SARS-CoV-2 vaccines in naive and previously infected individuals

Background Two mRNA vaccines, Pfizer-BNT162b2 and Moderna-mRNA-1273, obtained the Emergency Use Listing by WHO for preventing COVID-19. However, little is known about the difference in antibody responses induced by these two mRNA vaccines in naive and previously infected (PI) individuals. Method We investigated the levels of anti-S-RBD (total, IgG and IgA) levels in naive and PI individuals, 1-13 (median = 6) weeks following the second dose of either vaccine. Results in the naive-vaccinated group, the mRNA-1273 vaccine induced significantly higher levels of anti-S-RBD total antibodies (3.5-fold; P < 0.001), IgG (2-fold, P < 0.01) and IgA (2.1-fold, P < 0.001) as compared with the BNT162b2 vaccine. In addition, both vaccines produced significantly higher anti-S-RBD total antibody levels in the PI-group compared with naive-vaccinated group. The PI group elicited a higher level of anti-S-RBD IgG than the naive-BNT162b2 (P = 0.05), but not more than the naive-mRNA-1273 (P = 0.9) group. Interestingly, the PI vaccinated group elicited a comparable level of IgA ratio to the naive-mRNA-1273 group but significantly higher than the naive-BNT162b2 group (1.6-fold, P < 0.001). Conclusion Our results showed that the PI-vaccinated group produces a higher level of antibodies than the naive vaccinated group, particularly for those vaccinated with BNT162b2.

Automated summary

The study found that individuals with prior infection produced higher levels of antibodies compared to those who were vaccine-naive, especially for individuals vaccinated with BNT162b2.