Update: New Information Muddies the Waters on a COVID Vaccine–Myocarditis Connection

A few months ago, we shared news about a study indicating that the threat of myocarditis was greater for patients who got COVID-19 than for people who received a COVID vaccine and did not become infected. Now a study just published in the Journal of the American Medical Association raises new questions about a possible connection. Analysis of 1,626 cases of myocarditis showed rates were increased in vaccinated patients across age and sex strata, but highest after the second dose of vaccine in males 12 to 15 years of age, followed by males 16 to 17 years of age, and then males 18 to 24 years of age. While this study doesn’t make a direct comparison between vaccine recipients and nonrecipients who became infected, the authors did conclude that “risk of myocarditis after receiving mRNA-based COVID-19 vaccines was increased across multiple age and sex strata and was highest after the second vaccination dose in adolescent males and young men. This risk should be considered in the context of the benefits of COVID-19 vaccination.”