Comparison of the Immune Responses to COVID-19 Vaccines in Bangladeshi Population

Background: The adaptive immune response is a crucial component of the protective immunity against SARS-CoV-2, generated after infection or vaccination. Methods: We studied antibody titers, neutralizing antibodies and cellular immune responses to four different COVID-19 vaccines, namely Pfizer-BioNTech, Moderna Spikevax, AstraZeneca and Sinopharm vaccines in the Bangladeshi population (n = 1780). Results: mRNA vaccines Moderna (14,655 +/- 11.3) and Pfizer (13,772 +/- 11.5) elicited significantly higher anti-Spike (S) antibody titers compared to the Adenovector vaccine AstraZeneca (2443 +/- 12.8) and inactivated vaccine Sinopharm (1150 +/- 11.2). SARS-CoV-2-specific neutralizing antibodies as well as IFN-gamma-secreting lymphocytes were more abundant in Pfizer and Moderna vaccine recipients compared to AstraZeneca and Sinopharm vaccine recipients. Participants previously infected with SARS-CoV-2 exhibited higher post-vaccine immune responses (S-specific and neutralizing antibodies, IFN-gamma-secreting cells) compared to uninfected participants. Memory B (B-MEM), total CD8(+)T, CD4(+) central memory (CD4(CM)(+)) and T-regulatory (T-REG) cells were more numerous in AstraZeneca vaccine recipients compared to other vaccine recipients. Plasmablasts, B-regulatory (B-REG) and CD4(+) effector (CD4(EFF)(+)) cells were more numerous in mRNA vaccine recipients. Conclusions: mRNA vaccines generated a higher antibody response, while a differential cellular response was observed for different vaccine types, suggesting that both cellular and humoral responses are important in immune monitoring of different types of vaccines.

Automated summary

This study investigated the immune response of the Bangladeshi population to four different COVID-19 vaccines. The results showed that mRNA vaccines generated a higher antibody response, while different vaccine types had differential cellular responses.