A newly released internal HHS memorandum says federal reviewers classified seven pediatric deaths as "probably" or "possibly" related to cardiac complications that followed COVID-19 vaccination. The cases, which involved myocarditis, cardiomyopathy and fatal arrhythmia, have raised fresh oversight questions in Washington. The review does not calculate incidence rates or claim definitive causation.
The memorandum, dated Dec. 5, 2025, was prepared for the Senate Permanent Subcommittee on Investigations and was made public this month. As detailed in a document posted by Sen. Ron Johnson, reviewers examined 96 unique pediatric death reports filed to the Vaccine Adverse Event Reporting System. The document classified five deaths as "possible" and two as "probable" in relation to vaccination. Local coverage of the memo's release was reported by the Tampa Free Press.
What the review found
The memo says all seven verified cases involved cardiac events - five myocarditis or myopericarditis, one cardiomyopathy and one arrhythmia - and notes that "No cases were classified as certain in relation to COVID-19 vaccination." The authors reported the decedents were five males and two females, ages 7 to 16 (median 13), with symptom onset a median three days after vaccination (range 1 to 15 days). The analysis also records that all seven events followed Pfizer-BioNTech doses, six after the original monovalent formula and one after a bivalent booster, and that autopsy reports were reviewed for every case.
Experts urge caution; VAERS limits
Public health experts told NBC News that the memo is an important signal but not proof of causation, since VAERS is a passive reporting system and individual entries can reflect coincidental events or incomplete information. Reporters and federal reviewers noted the analysis is constrained by the inherent limits of VAERS and that possible or probable classifications can be consistent with alternative explanations. Clinicians say the classifications described in the memo should prompt deeper investigation rather than immediate alarm.
Regulatory context
The memorandum identifies fatal myocarditis cases as "new safety information" under the Federal Food, Drug, and Cosmetic Act, a designation that can lead to labeling changes or other regulatory steps. The FDA required expanded myocarditis and pericarditis warnings for mRNA COVID-19 vaccines in mid-2025, according to the agency's safety updates, and the memo's authors noted that fatal outcomes were not previously described in product prescribing information. They said regulators and researchers will need active-surveillance studies to determine whether the reported deaths reflect a measurable increase in risk.
What parents should know
Federal guidance stresses that VAERS is an early-warning tool and that "it is generally not possible to find out from VAERS data if a vaccine caused the adverse event," according to the VAERS FAQ. Parents who are worried about symptoms after vaccination are advised to consult their pediatrician. Experts say population-level studies and verified clinical data, not VAERS reports alone, are needed to determine whether these rare reports represent vaccine-caused harms.
