The FDA is forcing Pfizer and Moderna to use expanded warning labels about the risks of heart damage tied to Covid vaccines.

The shots previously included warning labels about the rare risks of myocarditis, inflammation of the heart muscle, and pericarditis, inflammation of the sac-like lining surrounding the heart.

The new labels will expand that warning to certain age groups — specifically males aged 16 to 25 who appear to be at the highest risk of the rare complication.

The new guidance comes as an FDA analysis of insurance claims found myocarditis and pericarditis occurred in one in 125,000 doses of the 2023-2024 shots for children and adults under 65.

For men under 25, the risk was 19 per 500,000, or the equivalent of one in 250.

Experts caution there have been no US deaths directly tied to Covid vaccine – triggered myocarditis and that the Covid virus itself is linked to heart damage, meaning the benefits of vaccination might still outweigh the small risk.

The CDC previously acknowledged both conditions were known side effects of the vaccines but did not provide a number of cases.

It’s unclear exactly when the new labels will go into effect or if Pfizer or Moderna disputed the order.

The news comes after a Congressional investigation accused Biden White House officials of purposely covering up warnings about myocarditis in young people.

The report suggested a planned Health Alert Network (HAN) message from the CDC on myocarditis was not released, and drafts of the alert downplayed risks.

The order is also the latest in the Trump administration’s crackdown on Covid vaccines.

Last week, reports from Department of Health and Human Services suggested the shots would no longer be routinely recommended for pregnant women, children and teens in the US.

And the FDA announced earlier this week that updated Covid vaccines would no longer be automatically approved for use without clinical safety trials.

With myocarditis, it’s thought that the immune system may register mRNA in Covid vaccines as a threat, leading the immune system to attack itself and cause inflammation of the myocardium, the heart’s muscle.

This same mechanism has been linked to pericarditis, which leads to inflammation of the pericardium, the sac surrounding the heart.

Both conditions have been linked to viruses like the common cold and hepatitis, as well as Covid.

While most cases are mild, in rare instances, myocarditis can damage the heart and make it difficult for it to pump blood, eventually leading to heart failure, heart attack, and stroke.

CDC officials told the FDA’s vaccine advisors last month that acute myocarditis ‘tends to resolve quickly’ after vaccination.

The CDC’s voluntary side effect reporting database VAERS, has logged over 1,600 cases of myocarditis in the US, primarily in young men 12 to 29 after they received a Pfizer or Moderna vaccine.

The FDA said the call for new warnings was spurred by data from the agency’s safety surveillance system and results from an October study of people who developed Covid vaccine-associated myocarditis.

Scientists followed up with people who suffered chest pain and elevated levels of troponin in their blood, a protein that signals heart damage. Most of the participants were adolescent males.

The researchers wrote in the study, which was co-authored by FDA officials: ‘While their clinical course was nearly always mild with a low prevalence and extent of cardiac dysfunction, myocardial injury was common.’

Currently, there is no conclusive evidence of deaths in the US directly caused by myocarditis from Covid vaccines.

For example, a 2023 Oregon study reviewing death certificates found no fatalities linked to vaccine-induced myocarditis in individuals aged 16–30.

However, some researchers caution that underreporting is possible due to gaps in America’s healthcare system, where mild or atypical cases may go unrecorded.

Still, the consensus among health authorities is that fatal outcomes from vaccine-related myocarditis – if they occur – are extremely rare, while the risks of severe Covid, including heart damage, remain well-documented.

Written by Emily Joshu Sterne for the Daily Mail ~ May 22, 2025

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