COVID-19 Vaccine Labels Updated With Expanded Warnings About Risk of Heart Inflammation
The Food and Drug Administration directed manufacturers to update the labels.
Zachary Stieber
Senior Reporter
6/26/2025|Updated: 6/26/2025
Federal regulators on June 25 updated labels for the Pfizer-BioNTech and Moderna COVID-19 vaccines to expand warnings regarding heart inflammation.
The updated labels state that myocarditis, inflammation, and a related condition called pericarditis have occurred following receipt of one of the shots “most commonly in males 12 years through 24 years of age.”
The Food and Drug Administration said in letters to the vaccine manufacturers earlier this year that they should update warnings on the inflammation to reflect available information.
The previous labels said that the highest observed risk of myocarditis after Pfizer vaccination was in males aged 12 to 17 while the highest observed risk following Moderna vaccination was in males aged 18 to 24.
Richard Forshee, acting director of the FDA’s Office of Biostatistics and Pharmacovigilance pointed to newer research, including a 2024 FDA study that found that some myocarditis patients had signs of heart scarring months after vaccination.
The vaccine makers could have challenged the directives, but instead opted to revise the labeling to comply with them, according to letters made public on Wednesday.
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Pfizer, BioNTech, and Moderna did not return inquiries. The vaccines from the companies were the first to use messenger ribonucleic acid (mRNA) technology and receive clearance in the United States.
They were administered to hundreds of millions of people during the COVID-19 pandemic, and some people continue to receive the vaccines.
“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,” the FDA said in a statement.
As part of the approvals of the vaccines, the manufacturers are also conducting studies assessing the long-term impacts on the hearts of recipients.
The new labels state that the estimated incidence of myocarditis or pericarditis within seven days of a dose of one of the vaccines is eight cases per million doses in people ages 6 months through 64, and 27 cases per million doses in males ages 12 to 24.
“In most people who have had myocarditis or pericarditis after receiving an mRNA COVID-19 vaccine, symptoms have gone away a few days after receiving treatment with medicines used to reduce inflammation,” the labels state. However, some individuals who suffered inflammation following vaccination had signs of injury to their heart months later, a study using cardiac magnetic resonance imaging found.
“It is not known if these heart MRI findings might predict long-term heart effects of myocarditis,” the labels state. “Studies are underway to find out if there are long-term heart effects in people who have had myocarditis after receiving an mRNA COVID-19 vaccine.”
The rate of myocarditis following vaccination with one of the currently available vaccines was down to two cases per million doses in people aged 12 to 39, or lower than the background rate, compared to a peak of 38 per million doses in 2020 and 2021, according to data from the Centers for Disease Control and Prevention’s Vaccine Safety Datalink presented to a government advisory panel on Wednesday.
The FDA considers data from its monitoring system superior because it was stratified by gender and in more narrow age ranges, Dr. Tracy Hoeg, an FDA official, told the meeting.
The FDA first added warnings to the labels for the vaccines in June 2021, several months after officials learned of post-vaccination myocarditis cases. Death certificates and other data have identified some post-vaccination deaths as being caused by heart inflammation after vaccination.
The CDC states on its website regarding clinical considerations for COVID-19 vaccines and myocarditis that “COVID-19 vaccination is recommended for everyone ages 6 months and older in the United States for the prevention of COVID-19.” The webpage, dated Oct. 10, 2023, is one of multiple pages that have not been updated to reflect that healthy children and pregnant women are no longer advised to get a COVID-19 vaccine. |
