FDA finalizes new heart warnings for COVID-19 vaccines
The U.S. Food and Drug Administration (FDA) has finalized and announced new warnings for COVID-19 vaccines manufactured by Pfizer and Moderna that highlight certain cardiac risks. These expanded warnings, first proposed in letters sent to the companies in April, provide additional information about the potential risks of myocarditis and/or pericarditis associated with the two vaccines. Myocarditis and pericarditis can both potentially lead to long-term heart damage.
This update covers the Comirnaty vaccine from Pfizer and the Spikevax vaccine from Moderna
Pfizer and Moderna have included text about myocarditis and pericarditis in the labeling for these vaccines since 2021. However, the FDA wanted more information added to these warnings that specifically spells out the increased risks for young men.
The labeling for these vaccines is now required to include the following text:
Based on analyses of commercial health insurance claims data from inpatient and outpatient settings, the estimated unadjusted incidence of myocarditis and/or pericarditis during the period 1 through 7 days following administration of the 2023-2024 Formula of mRNA COVID-19 vaccines was approximately 8 cases per million doses in individuals 6 months through 64 years of age and approximately 27 cases per million doses in males 12 through 24 years of age.
Follow-up information on cardiovascular outcomes in hospitalized patients who had been diagnosed with COVID-19 vaccine-associated myocarditis is available from a longitudinal retrospective observational study. Most of these patients had received a two-dose primary series of an mRNA COVID-19 vaccine prior to their diagnosis. In this study, at a median follow-up of approximately 5 months post-vaccination, persistence of abnormal cardiac magnetic resonance imaging (CMR) findings that are a marker for myocardial injury was common. The clinical and prognostic significance of these CMR findings is not known.
The agency emphasized that it plans to keep tracking the safety of COVID-19 vaccines going forward.
“Continuous monitoring and assessment of the safety of all vaccines, including the mRNA COVID-19 vaccines, is an FDA priority and we remain committed to informing the public when we learn new information about these vaccines,” according to an FDA Safety Communication dated June 25. “In addition, as part of the approvals of Comirnaty and Spikevax, each manufacturer is required by FDA to conduct a study to assess if there are long-term heart effects in people who have had myocarditis after receiving an mRNA COVID-19 vaccine. These studies are underway.”
Additional context about myocarditis and COVID-19 vaccines
Acute myocarditis and other related conditions have been seen in a small number of patients after receiving a COVID-19 vaccination. The long-term impact of this risk has been the subject of many clinical studies and debates over the past few years.
While the American College of Cardiology, American Heart Association and other U.S. healthcare organizations have consistently supported patients receiving COVID-19 vaccines, some critics have remained adamant that even the smallest risk of these side effects is too high.
Michael has more than 19 years of experience as a professional writer and editor. He has written at length about cardiology, radiology, artificial intelligence and other key healthcare topics.