Soon after the first COVID-19 vaccines appeared in 2021, reports of rare cases of heart inflammation, or myocarditis, began to surface.
In most instances, the myocarditis has been mild and responded well to treatment, though up to four potentially mRNA vaccine-related deaths from myocarditis in adults have been reported worldwide. No known verified deaths of children have been reported based upon publicly available data. The exact number remains a topic of very heated debate because of variability in the reporting of possible myocarditis-related deaths.
Studies have largely confirmed that the overall myocarditis risk is significantly higher after an actual COVID-19 infection compared with vaccination, and that the prognosis following myocarditis due to the vaccine is better than from infection. The specific myocarditis risk varies by age and has been debated because of differing views among a small group of physicians related to risk tolerance and support for or against COVID-19 immunization for specific age groups.