Myocarditis after BNT162b2 mRNA Vaccine against Covid-19 in Israel

This study examines the incidence of myocarditis following BNT162b2 mRNA COVID-19 vaccination in Israel, where over 5.1 million individuals were fully immunized by May 2021. Active surveillance identified 136 definitive or probable myocarditis cases among 142 reported post-vaccination, with 95% presenting mild symptoms and one fatal fulminant case. The risk was highest in young males (16–19 years), with a standardized incidence ratio of 13.60 after the second dose. The overall rate ratio for myocarditis within 30 days post-second dose was 2.35 compared to unvaccinated individuals, peaking at 8.96 in males aged 16–19. Most cases occurred shortly after the second dose, suggesting a temporal association. Despite the low absolute risk (1 in 6,637 young males), findings indicate a causal link between vaccination and myocarditis, particularly in younger male recipients.

This study examines the incidence of myocarditis following BNT162b2 mRNA COVID-19 vaccination in Israel, where over 5.1 million individuals were fully immunized by May 2021. Active surveillance identified 136 definitive or probable myocarditis cases among 142 reported post-vaccination, with 95% presenting mild symptoms and one fatal fulminant case. The risk was highest in young males (16–19 years), with a standardized incidence ratio of 13.60 after the second dose. The overall rate ratio for myocarditis within 30 days post-second dose was 2.35 compared to unvaccinated individuals, peaking at 8.96 in males aged 16–19. Most cases occurred shortly after the second dose, suggesting a temporal association. Despite the low absolute risk (1 in 6,637 young males), findings indicate a causal link between vaccination and myocarditis, particularly in younger male recipients.