The U.S. Food and Drug Administration (FDA) has updated its warning labels for the two most widely used COVID-19 vaccines — Pfizer and Moderna — to provide more detailed information about the rare risk of myocarditis, an inflammation of the heart muscle. The condition has primarily been observed in younger males and was first identified shortly after the vaccines became widely available in 2021.More Detailed Labeling After FDA RequestThough both vaccine makers had already included myocarditis warnings in their prescribing information, the FDA formally asked them in April to expand these details. The agency can mandate label changes, but such updates are typically negotiated with drugmakers.The revised warning now estimates that 8 cases of myocarditis occur per 1 million people who received the 2023–2024 COVID vaccines in the age group of 6 months to 64 years. The update also clarifies that the risk is highest among males aged 12 to 24, a slight expansion from the earlier label, which focused on boys aged 12 to 17.Conflicting Findings Within U.S. AgenciesInterestingly, this update appears to contradict some earlier findings from the Centers for Disease Control and Prevention (CDC). The CDC had previously stated that, based on vaccine safety data through 2022, there was no significant increase in myocarditis risk linked to COVID-19 vaccines. They also pointed out that vaccine-related myocarditis cases tend to be mild and resolve quickly, especially when compared to heart inflammation caused by the COVID-19 infection itself.New Advisory Panel Brings Vaccine ScrutinyThe timing of the FDA’s label change aligns with broader shifts in vaccine policy under the leadership of Health Secretary Robert F. Kennedy Jr. A longtime vaccine skeptic, Kennedy recently dismissed all 17 members of the CDC's vaccine advisory panel and appointed a new group, some of whom have expressed anti-vaccine sentiments in the past. This week marked their first meeting, where ongoing use of COVID-19 vaccines, especially among vulnerable groups like pregnant women, was discussed.New Restrictions and Requirements Under ReviewFDA Commissioner Dr. Marty Makary, appointed by Kennedy, has taken several steps to limit the scope of COVID-19 vaccine recommendations. Recently, he restricted annual COVID-19 booster shots to seniors and high-risk individuals. Makary has also suggested that seasonal updates to vaccines — meant to better match circulating virus strains — should be treated as entirely new products requiring additional clinical testing.Focus Should Be on Understanding Risk, Not Curtailing VaccinesWhile acknowledging that myocarditis should not be dismissed, some public health experts believe the FDA’s latest approach is flawed. “We should be investigating who is prone to myocarditis to see if we can predict and mitigate that risk,” said Dr. Robert Morris, a public health specialist at the University of Washington. “They are right to raise the concern, but not with these broad warning changes," as reported by Associated Press. Makary and his team had previously questioned the government’s booster recommendations. In a 2022 paper, he and two FDA colleagues argued that mandating boosters for young people might lead to more harm than good, a position that diverged from CDC guidance at the time.