While rare, some people have developed myocarditis (inflammation of the heart muscle) or pericarditis (inflammation of the tissue that forms a sac around the heart) after receiving the Pfizer, Moderna or Novavax vaccine. Usually the resulting myocarditis and pericarditis are minor, and people who receive treatment for their symptoms quickly get better.
Depending on your age and gender, your chance of getting this type of inflammation after the COVID-19 vaccine is very unlikely: somewhere between one in 20,000 and one in 100,000.
According to the CDC, myocarditis and pericarditis from a COVID-19 vaccine happen most frequently in male adolescents and young adults after receiving a second dose. But even within this group, the conditions happen very infrequently.
Because the risk is small and the benefits of the vaccine are significant, the CDC still recommends a COVID-19 vaccine for everyone, including young men and people with heart disease.