A newly released internal memorandum from the U.S. Food and Drug Administration (FDA) is renewing scrutiny over what federal health officials knew about serious cardiac events following mRNA COVID-19 vaccination in children and how much of that information reached the public during the height of the pandemic.
The 68-page document, released by Sen. Ron Johnson, reviewed 96 pediatric death reports submitted to the Vaccine Adverse Event Reporting System (VAERS) through Aug. 14, 2025. FDA reviewers determined that seven deaths were either “probable” or “possible” cases linked to COVID-19 vaccination, with myocarditis and other forms of cardiac injury appearing repeatedly throughout the agency’s analysis.
The memorandum, dated Dec. 5, 2025, emerged after months of pressure from Johnson’s Permanent Subcommittee on Investigations, which has been examining whether federal health agencies minimized or failed to act on vaccine safety signals during the Biden administration.
Although the FDA concluded that none of the reviewed deaths met its standard for “certain” causality, agency reviewers classified two deaths as “probably” related to vaccination and five others as “possibly” related. According to the memorandum, “probable” cases involved fatalities unlikely to be explained by another cause, while “possible” cases still carried competing explanations.
All seven cases involved cardiac complications, and five involved myocarditis, an inflammatory heart condition that federal regulators have publicly acknowledged as a known risk associated with mRNA COVID-19 vaccines, particularly in adolescent and young adult males.
The FDA repeatedly emphasized throughout the report that VAERS data alone cannot establish definitive causation. Reviewers cited incomplete medical records, inconsistent autopsy findings, reporting bias, and the absence of control groups as significant limitations within passive surveillance systems.
The memorandum also reveals that FDA reviewers internally viewed several fatal myocarditis cases as “new safety information” that could justify updated warning labels discussing fatal myocarditis outcomes following mRNA vaccination. Yet those warnings never appeared publicly in the form described within the memo.
Johnson’s office framed the report as evidence that regulators possessed more serious safety concerns than previously disclosed. In a May 12 letter to Health and Human Services Secretary Robert F. Kennedy Jr., Johnson stated the agency had produced an internal memorandum describing pediatric deaths following vaccination, including cases categorized as “possibly” or “probably” related to the shots.
The newly released document also follows earlier controversy surrounding comments from former FDA vaccine official Dr. Vinay Prasad, who reportedly wrote in a November 2025 memo that “at least 10 children” died after COVID-19 vaccination. That statement generated widespread debate after outside experts argued that the underlying evidence had not been publicly presented.
The FDA memo released by Johnson appears narrower and more cautious in its language than those earlier claims. Still, it confirms that agency reviewers internally identified pediatric myocarditis deaths they believed warranted heightened regulatory attention.
The report arrives amid broader congressional scrutiny of federal vaccine safety monitoring systems, particularly VAERS and the FDA’s handling of adverse-event data during the pandemic.
Johnson’s subcommittee recently released a separate report alleging that FDA officials failed to fully investigate statistically significant safety signals detected through alternative data-mining methods during 2021. According to that investigation, internal analyses identified potential signals involving sudden cardiac death, Bell’s palsy, pulmonary infarction, and myocardial injury that were not captured through the FDA’s primary surveillance methodology.
In June 2025, the agency required updated warning labels for Pfizer and Moderna COVID-19 vaccines to include additional information about myocarditis and pericarditis risk, particularly among males ages 12 through 24. Those updated labels acknowledged ongoing concerns surrounding persistent cardiac MRI abnormalities in some individuals diagnosed with vaccine-associated myocarditis.
The newly disclosed pediatric death review suggests federal regulators did not move quickly enough to inform physicians, parents, and the public about the most severe outcomes being examined internally. Even so, the report provides one of the clearest acknowledgments to date that FDA reviewers considered several pediatric myocarditis deaths following COVID-19 vaccination serious enough to justify expanded safety warnings.
