Federal health officials said Thursday they’re seeing rare but higher-than-expected cases of a heart issue called myocarditis among adolescents and young adults who received their second shot of one of the mRNA Covid-19 vaccines.
The data are preliminary and limited, and experts are still trying to determine if there is indeed a link or if there is no connection at all. Officials from the Centers for Disease Control and Prevention and the Food and Drug Administration also said it was too early to establish a rate for how frequently myocarditis — an inflammation of the heart muscle — might occur, particularly for different age groups. It appears the cases were more common in men than women, though the experts noted that men generally have higher rates of myocarditis. It’s also more common in younger adults at a baseline level.