The US Food and Drug Administration is planning an unusual and controversial step: adding a black box warning to COVID vaccines, the most severe regulatory warning in the FDA’s arsenal, according to a report Friday by CNN.
The plan, which could be unveiled by the end of the year, has already sparked fierce criticism from public health experts, who accuse the Trump administration of undermining trust in vaccines for political reasons and without presenting detailed scientific data to justify such a move.
According to CNN, which cited two sources familiar with the matter, the initiative is being led by Dr. Vinay Prasad, the FDA’s chief medical and scientific officer and head of the Center for Biologics Evaluation and Research. Prasad, a controversial figure who publicly criticized COVID vaccination policy before assuming his current role, sent a memo to center staff last month claiming that at least 10 children died “after and because of” receiving a COVID vaccine.
The memo did not include supporting data or detailed information. Prasad promised “rapid action” on the issue. According to the memo, the claim is based on a preliminary analysis of 96 deaths reported between 2021 and 2024, which he described as “likely, probably or possibly related to vaccination.”
“This would be the first time the FDA acknowledges that COVID vaccines caused the deaths of American children,” Prasad wrote last month.
A spokesperson for the U.S. Department of Health and Human Services said Thursday that the FDA “takes very seriously any death reported in association with a regulated medical product,” but declined to confirm or deny plans to add a warning to COVID vaccines. The spokesperson added that “any claims about what the FDA will do are pure speculation unless and until the agency announces them,” and rejected outright allegations that “anyone on our team is attempting to manufacture evidence.”
A black box warning appears at the top of official prescribing information for a drug or vaccine and is intended to alert providers and patients to serious risks, including death, life threatening reactions or permanent disability, that must be weighed against the benefits of treatment.
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The coronavirus. mRNA vaccines were among the most important tools in curbing the pandemic
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Such warnings appear on opioid medications, which carry risks of addiction, overdose and death, on the acne drug Accutane due to the risk of severe birth defects during pregnancy, and on another vaccine used against smallpox and mpox that warns of complications such as myocarditis and encephalitis.
Focus on myocarditis
Black box warnings are not always permanent. Just last month, the FDA removed such a warning from certain hormone therapies used for menopause, reversing a decision that had affected the health of millions of women for more than two decades.
The plan to add a warning to COVID vaccines has not been finalized and could still change. It remains unclear whether the warning would apply only to mRNA vaccines made by Pfizer and Moderna or also to other COVID vaccines, and whether it would cover all age groups.
Three COVID vaccines are currently authorized for use in the United States: two mRNA vaccines from Pfizer and Moderna, and one from Novavax, which uses a more traditional protein based technology. Israel has shifted over the past year to using the Novavax vaccine, which is not based on mRNA technology.
Both Moderna and Pfizer have reiterated the safety of their vaccines. Moderna said its vaccine is “closely monitored by Moderna, the U.S. FDA and regulators in more than 90 countries,” adding that with more than 1 billion doses distributed worldwide, “safety monitoring systems have not identified any new or hidden safety concerns in children or pregnant women.” Pfizer declined to comment.
According to reports, Prasad has focused on the rare side effect of myocarditis following mRNA vaccination. The condition was identified early in the vaccine rollout, when the first and second doses were administered just weeks apart, and was observed mainly in adolescent boys and young men.
A presentation by the Centers for Disease Control and Prevention in June found that most adolescents and young adults recovered from post vaccination myocarditis, with no known deaths or heart transplants. Rates have declined significantly in recent years after the recommended interval between doses was extended for those receiving mRNA vaccines.
In May, however, the FDA required safety warnings in the official labeling of Pfizer and Moderna vaccines regarding the risk of myocarditis and pericarditis, expanding the warning to a broader age range. Current labeling states that “the observed risk was highest in males ages 12 to 24.”
One study estimated that during their first year of use, COVID vaccines prevented nearly 20 million deaths worldwide.
The rapid development of COVID vaccines during the pandemic, under the initiative known as Operation Warp Speed, was a major achievement of President Donald Trump’s first term, one that several Republican lawmakers have recently said deserved a Nobel Peace Prize. In his second term, however, Trump appointed Robert F. Kennedy Jr., a prominent vaccine skeptic, as his health secretary, drawing sharp criticism from public health experts and members of Congress.
The Kennedy influence
Kennedy and his allies have long questioned the safety and effectiveness of COVID vaccines, which were tested in placebo controlled trials involving about 75,000 participants and administered to millions of people in the United States and worldwide during the pandemic.
Israel was among the first countries to deploy Pfizer’s vaccine and shared safety data with the company. Prasad himself has been a polarizing figure both in his FDA role and previously as a podcast host and professor of epidemiology and biostatistics at the University of California, San Francisco. He was appointed director of CBER in May under FDA Commissioner Dr. Marty Makary.
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The new approach led by Robert F Kennedy Jr, alongside FDA Commissioner Dr Marty Makary
(Photo: Elizabeth Frantz/ Reuters)
On Tuesday, the group Children’s Health Defense, which Kennedy led before his presidential bid, filed a petition calling on the FDA to revoke licenses for COVID vaccines. The organization claims mRNA vaccines are mislabeled because they were initially authorized under emergency use standards.
The Health and Human Services Department said this week that the FDA is reviewing whether deaths “across multiple age groups” could be linked to COVID vaccines.
Dr. Aaron Kesselheim, who directs the Program on Regulation, Therapeutics and Law at Harvard University, told CNN that black box warnings can be initiated either by manufacturers or by the FDA. Typically, however, the agency publicly announces that it is examining a safety concern and may convene an advisory committee of independent external experts to review the data and provide recommendations.
None of those steps have occurred in this case. The FDA declined to say whether it plans to hold an advisory committee meeting.
“My concern here is that there is no process,” Kesselheim said. “There is no opportunity for good faith discussion and review of the data underlying this decision. My concern is that it will look like yet another decision made by this FDA based on political objectives rather than rigorous, public scientific review.”