FDA Updates COVID Vax Labels to Include Heart Risk Warnings

The Food and Drug Administration is requiring Pfizer and Moderna to expand warnings on the labels of their COVID-19 vaccines for the risk of heart inflammation in adolescents and young men.

The agency cited updated estimates of cases of myocarditis and pericarditis — inflammation of heart muscle and surrounding tissue — and a post-approval study showing the persistence of heart abnormalities months after getting the mRNA shots.

The label changes were posted on Wednesday and communicated in April 17 letters to the companies. CBS News first reported the notices.

The agency said an analysis of insurance claims found an incidence of 8 cases per million doses for the 2023-2024 formulas of the shots.

The updated warnings apply to males ages 16 to 25. Earlier warnings of heart issues for Pfizer-BioNTech's vaccine covered males 12 to 17, and for Moderna's, males 18 to 24.

Heart inflammation has been a known, but rare, side effect linked to the vaccines since early in the pandemic.

The Centers for Disease Control in 2021 concluded there was a "likely association," especially in adolescents and young adults, but that there still was a benefit for the group to get the shot.

While cases were rare, they drew concern from scientists responsible for evaluating risks who at the time were weighing whether to recommend the vaccines for children younger than 12.

CDC officials told an agency advisory committee earlier this year that acute myocarditis after a COVID-19 vaccine tends to resolve itself quickly, and that it's associated with less severe cardiovascular events than myocarditis after COVID-19 infection.

The labeling orders come amid bigger changes in how FDA is regulating COVID vaccines.

The agency on Tuesday said it would require drugmakers to conduct more scientific studies before approving updated COVID-19 vaccines for healthy adults under age 65 — a move that will likely limit access to the shots to seniors and people with pre-existing conditions.

They also coincide with a Senate hearing held Wednesday to probe whether federal health officials downplayed the risk of myocarditis after COVID-19 vaccination.