FDA requires drugmakers update, expand warning about COVID shots' heart risks

The Food and Drug Administration has expanded its warnings on two COVID-19 vaccines regarding a rare heart side effect, mostly impacting young males.

The side effect, Myocarditis, is a type of heart inflammation that is usually mild.

Prescribing information from the two drugmakers – Moderna and Pfizer – already advises doctors about the issue. But the FDA sent letters this spring to the drugmakers, requesting they update and expand the warnings to provide more detail about the problem and to cover a larger group of patients, according to the Associated Press. 

The new warning lists the risk of myocarditis as 8 cases per 1 million people who got the 2023-2024 COVID shots between the ages of 6 months and 64 years old. The new label also states the problem has been most common among males 12 to 24, compared to the previous one that stated it mostly occurs in 12- to 17-year-olds.

The Centers for Disease Control and Prevention previously stated there was no increased risk of myocarditis detected in government vaccine injury databases for COVID-19 shots dating back to 2022, the wire service also reports.