Discussion
myocarditis
REACTOGENICITY, ADVERSE EVENTS, MYOCARDITIS
The expansion of the ongoing PREVENT-19 trial into more than 2200 racially and ethnically diverse adolescents in the US demonstrates that NVX-CoV2373 appears safe and effective (as determined by predefined immunogenicity criteria). Neutralizing antibody responses on postvaccination day 35 were noninferior for both GMFR and serologic response to those observed in young adults from PREVENT-19, in whom a high degree of protective efficacy (90.4% [95% CI, 82.9%−94.6%]) was demonstrated.The high short-term vaccine efficacy of NVX-CoV2373 for the prevention of COVID-19 in adolescents aged 12 through 17 years corroborated the earlier results from the adult portion of the study.No safety concerns were identified during the follow-up period reported herein (median, 71 [IQR, 65–77] days after dose 2, with >84% of participants followed up for at least 60 days for this analysis). Reactogenicity was mild to moderate in severity, self-limited, and, as expected, more frequent and more severe after the second vaccination. By contrast, similar rates of unsolicited adverse events (including serious or severe adverse events) were observed between vaccine and placebo recipients. However, given the sample size, this study did not have the power to identify rare adverse events, such as myocarditis following vaccination.Neutralizing antibodies and anti–S-binding IgG antibodies at day 35 (ie, 14 days after the second vaccine dose) have been correlated with vaccine efficacy for NVX-CoV2373.