A U.S. Food and Drug Administration (FDA) safety official recommended adding a warning about fatal myocarditis to mRNA COVID-19 vaccine labels in December 2025, after an agency review identified several pediatric deaths as possibly or probably related to vaccination.
More than 10 months later, the agency hasn’t added the warning.
According to documents obtained by investigative journalist Paul D. Thacker, an FDA pharmacovigilance expert — Dr. Meghna Alimchandani — emailed agency leadership on Dec. 5, 2025, formally recommending that a warning for fatal myocarditis be added to mRNA COVID-19 vaccine labels.
Her recommendation followed an internal memo from Dr. Vinay Prasad, then-head of the FDA Center for Biologics Evaluation and Research (CBER). The memo, later leaked to The New York Times, revealed that agency researchers had initially identified “no fewer than 10” child or teen deaths tied to vaccine-induced myocarditis.
However, documents released in June by Sen. Ron Johnson (R-Wis.) showed that a month after CBER identified the 10 child deaths, it reduced the number of deaths to seven and downgraded the probability that the vaccines were directly responsible.
Several former FDA officials told RealClearInvestigations that the leaked memos and documents — along with reporting by The New York Times and other news outlets — “appears to have unsettled the FDA’s safety office,” leading the agency to reduce the number of child deaths that it linked to the COVID-19 shots.
In May 2025, the FDA directed Pfizer and Moderna to strengthen their COVID-19 vaccine label warnings by expanding the age group at risk for vaccine-related myocarditis and pericarditis and warning that myocardial injury can be lasting — but the warning about fatal outcomes has never been added.
Thacker suggested that overlapping political, pharmaceutical and media interests may have led to the FDA decision not to add the warning.
He attributed the lack of action partly to the Trump administration’s investment in Operation Warp Speed, which accelerated vaccine development in 2020, and to what he describes as the Biden administration’s reluctance to publicize findings that could undermine its vaccination policies.
Drug safety advocate Kim Witczak, a former member of the FDA Psychopharmacologic Drugs Advisory Committee, told The Defender that the warning label issue should not be partisan.
“This isn’t about Republicans or Democrats, Trump, Biden or RFK Jr., it’s about the American public’s right to know,” Witczak said. “If FDA scientists identified credible evidence of fatal myocarditis and recommended updating the COVID vaccine labels, why hasn’t that happened? Who made that decision?”
