Immunogenicity and reactogenicity of SARS-CoV-2 vaccines BNT162b2 and CoronaVac in healthy adolescents

We present an interim analysis of a registered clinical study (NCT04800133) to establish immunobridging with various antibody and cellular immunity markers and to compare the immunogenicity and reactogenicity of 2-dose BNT162b2 and CoronaVac in healthy adolescents as primary objectives. One-dose BNT162b2, recommended in some localities for risk reduction of myocarditis, is also assessed. Antibodies and T cell immune responses are non-inferior or similar in adolescents receiving 2 doses of BNT162b2 (BB, N = 116) and CoronaVac (CC, N = 123) versus adults after 2 doses of the same vaccine (BB, N = 147; CC, N = 141) but not in adolescents after 1-dose BNT162b2 (B, N = 116). CC induces SARS-CoV-2 N and N C-terminal domain seropositivity in a higher proportion of adolescents than adults. Adverse reactions are mostly mild for both vaccines and more frequent for BNT162b2. We find higher S, neutralising, avidity and Fc receptor-binding antibody responses in adolescents receiving BB than CC, and a similar induction of strong S-specific T cells by the 2 vaccines, in addition to N- and M-specific T cells induced by CoronaVac but not BNT162b2, possibly implying differential durability and cross-variant protection by BNT162b2 and CoronaVac, the 2 most used SARS-CoV-2 vaccines worldwide. Our results support the use of both vaccines in adolescents. There are adverse events associated with COVID-19 vaccines, such as myocarditis for adolescents following receipt of SARS-CoV-2 mRNA vaccines. Here the authors compare the immunogenicity and reactogenicity of two widely available SARS-CoV-2 vaccines (BNT162b2, an mRNA vaccine, and CoronaVac, a whole-virus inactivated vaccine) in healthy adolescents.

Automated summary

This study compares the immunogenicity and reactogenicity of two widely available SARS-CoV-2 vaccines, BNT162b2 (an mRNA vaccine) and CoronaVac (a whole-virus inactivated vaccine), in healthy adolescents. The results show that the antibody and T cell immune responses in adolescents receiving two doses of either BNT162b2 or CoronaVac are similar to those seen in adults receiving two doses of the same vaccine. However, the immune response to a single dose of BNT162b2 in adolescents is not as robust. Additionally, CoronaVac induces a higher proportion of adolescents to have positive antibody responses compared to adults. Adverse reactions are generally mild for both vaccines, with BNT162b2 having slightly more frequent adverse reactions.