December 12, 2025
3 min read
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Health Experts Slam Possible FDA ‘Black Box’ Warning for COVID Vaccines
The FDA is reportedly considering the addition of high-level warning labels to COVID vaccines, a move that some experts say may cause unfounded concerns over safety
PATRICK T. FALLON/AFP via Getty Images
The U.S. Food and Drug Administration is reportedly weighing whether it will place a “black box” warning label on COVID vaccines, according to CNN, despite research and real-world data demonstrating their safety.
Black box warnings are the FDA’s highest health warning for drugs and medical devices. Adding them to COVID vaccines “would be an unprecedented action by the FDA and would likely result in significant reduction in use of the product,” says physician Robert Hopkins, medical director of the National Foundation for Infectious Diseases.
It’s unclear whether the warning, if applied, would be put on some or all the available COVID vaccines produced by Pfizer, Moderna and Novavax or if it would affect specific groups, such as pregnant people or children.
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The report comes a week after a leaked memo, allegedly written by the FDA’s chief medical and scientific officer Vinay Prasad, detailed plans to change COVID vaccine approvals and linked the deaths of 10 children to the vaccines, without evidence.
In response to Scientific American, Department of Health and Human Services spokesperson Andrew Nixon dismissed the claims as “pure speculation” and said that “the FDA takes very seriously any death that is attributed to a regulated medical product.”
Black box warnings, also called boxed warnings, are designed to inform people of major health risks associated with a drug, treatment or other medical intervention, including a vaccine, and generally indicate a risk of serious injury or life-threatening harm. Opioid painkillers carry such a warning, for example. The FDA has the power to add these labels, update them or remove them at any point as data becomes available to the agency.
More than 400 medications approved for use in the U.S. have a black box warning label. Vaccines with black box warnings “are exceedingly rare,” says Peter Chin-Hong, an infectious disease physician and a professor of medicine at the University of California, San Francisco, because vaccines undergo rigorous trials and safety and efficacy assessments before the FDA authorizes them for use.
And while some vaccines, such as the live ACAM2000 vaccine for smallpox and mpox, carry health risk warnings, these examples are “certainly nothing [as] big” as the FDA’s potential decision to put a black box warning on COVID vaccines, says Katelyn Jetelina, an epidemiologist and founder of the newsletter Your Local Epidemiologist.
“The science is clear: the benefits continue to outweigh the risks by a wide margin,” Jetelina says. “If FDA disagrees, transparency about their data and reasoning is essential. Closed-door analyses won’t cut it. Americans deserves better.”
The COVID vaccines have been safely administered to billions of people worldwide and have been shown to have prevented millions of deaths from the virus that causes the disease. Initial and ongoing safety monitoring continues to show the benefits of these vaccines outweigh the risk for most populations, Hopkins says.
He and other experts have expressed concern that a severe safety warning may ultimately impede access to the vaccines. A black box label may cause clinicians to be more cautious in recommending the shots to groups who are at high risk of severe COVID, such as children and pregnant people, Chin-Hong says.
If the black box label is added, “vaccine hesitancy will increase in the groups who need it the most,” he says. “But most of all, a continued erosion of trust in the proven power of vaccines in general will lead to more illness and deaths—and more suffering in Americans.”
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