Pfizer-BioNTech's coronavirus vaccine may be causing myocarditis in men between the ages of 16 and 30, Israel's Ministry of Health announced. Between December 2020 and May 2021, there were 275 cases of myocarditis among more than 5 million vaccinated people. Most patients spent no more than 4 days in the hospital, so 95% of the cases were classified as mild. Pfizer said it did not observe a higher than normal incidence of myocarditis, stressing that no link between the vaccine and the disease has been established.