The FDA is requesting Pfizer and Moderna update warning labels on their COVID-19 vaccines to more clearly communicate the risk of myocarditis and pericarditis, particularly in younger males. This follows new safety data and a 2024 FDA-funded study indicating rare but notable post-vaccination cardiac inflammation with potential for long-term myocardial injury.
Revised labeling for Moderna’s SPIKEVAX would include an estimated myocarditis rate of 38 cases per million in males aged 16–25, occurring within 1 to 7 days post-vaccination. The agency also wants updated language reflecting findings from follow-up MRIs that show signs of heart muscle injury in some patients months after developing vaccine-related myocarditis, although most showed improvement.
These changes are not yet mandatory. Pfizer and Moderna were given 30 days to comply or submit rebuttals; their responses remain undisclosed.
Follow MEDWIRE.AI for updates on vaccine safety and regulatory policy.
