Among over 192 million people vaccinated with mRNA-based COVID-19 vaccines, there were 1,991 reported cases of myocarditis, with most cases occurring in young males, particularly after the second vaccine dose.
The study found that myocarditis rates were significantly higher than expected, especially in adolescent males aged 12-17 and young men aged 18-24, with rates peaking at 105.9 per million doses in 16-17 year olds.
Most of the myocarditis cases in those under 30 showed abnormal heart test results, with 96% requiring hospitalization, but 87% of these patients had resolution of symptoms by the time of hospital discharge, commonly treated with anti-inflammatory drugs.
