The incidence of mRNA COVID-19 vaccine-associated myocarditis varies widely due to surveillance methods, with the highest risk observed in young men following the second dose, particularly with mRNA-1273 compared to BNT162b2.
Systematic Review
What is the incidence of myocarditis and pericarditis following mRNA COVID-19 vaccination, and how do vaccine type, demographics, and study characteristics influence these rates?
The reported risk of mRNA vaccine-associated myocarditis varies widely due to surveillance methods, but is highest in young men after the second dose, particularly with the mRNA-1273 vaccine.
Purpose: Early studies showed that the risks of mRNA vaccine-associated myocarditis and pericarditis are low but with substantial variation across studies. Study characteristics, ethnicity, vaccine types, dose intervals, and SARS-CoV-2 infection prevalence may influence the rates of myocarditis and pericarditis after mRNA vaccination in population-based studies. Methods: We comprehensively searched MEDLINE for relevant articles published before November 30, 2022. We also searched the websites of health authorities in several countries for unpublished surveillance data on myocarditis and pericarditis after mRNA vaccination. The outcome of interest was the incidence of myocarditis and pericarditis developed after mRNA vaccination for COVID-19. Results: A total of 17 studies form 10 countries were included for review. We noted that considerable heterogeneity in study characteristics, including surveillance method, case definition, and observation period, may partially be responsible for the widely varied reported rates. Studies from countries that adopted active surveillance reported higher rates than those using passive surveillance. Compared to BNT162b2 vaccine, mRNA-1273 may have a higher risk of myocarditis only in young men after the second dose. Our comparison of sex-, age-, vaccine type-, and dose-specific rates of myocarditis across countries did not support the hypothesis that individuals with recent SARS-CoV-2 infection and young Asian males were at higher risk. We also could not find sufficient evidence to conclude whether extending the between-dose interval could reduce myocarditis incidence following mRNA vaccination. Conclusion: Differences in the study characteristics must be fully considered when comparing the risks of mRNA vaccine-related myocarditis and pericarditis in different countries.
Lin et al. (Sun,) conducted a systematic review in Myocarditis and pericarditis. mRNA COVID-19 vaccination vs. Unvaccinated or different mRNA vaccine was evaluated on Incidence of myocarditis and pericarditis after mRNA vaccination. The incidence of mRNA COVID-19 vaccine-associated myocarditis varies widely due to surveillance methods, with the highest risk observed in young men following the second dose, particularly with mRNA-1273 compared to BNT162b2.