During my 15 years at the U.S. Food and Drug Administration (FDA) as a medical reviewer of drugs and vaccines, Special Assistant to the Commissioner, and founding director of the Office of Biotechnology, I developed great respect for the Agency. Many of the professionals boasted deep expertise in their arcane fields of science, medicine, and regulation, and had been there for many years. Sometimes, I thought approvals were granted more slowly than necessary, but generally, appropriate caution and integrity dictated decisions that could affect the health and safety of millions of Americans.
Over the past year, all that has changed. Huge numbers of staff have been fired or resigned, and appointees to leadership posts have been inconceivably poor choices—unqualified; lacking respect for science and public health; being guided by Health and Human Services Secretary Robert F. Kennedy Jr.’s unhinged, unscientific views; and making decisions that will undermine public health.
The worst may be yet to come.
For more than half a century, the FDA’s “black box” warning on drug labels has served as the agency’s strongest regulatory signal—a red flag reserved for medicines that carry a clear, serious, and well-established risk of death or irreversible harm. Opioids earn black boxes because they kill tens of thousands of Americans each year through addiction and overdose. ACAM2000, a live-virus smallpox and mpox vaccine used only in tightly controlled settings, carries one because of well-documented risks of myocarditis, encephalitis, and death. Isotretinoin (Accutane) bears one because it causes catastrophic birth defects if taken during pregnancy. Here is the black box warning on the label of Zyprexa, which is used to treat schizophrenia and bipolar disorder:
Against that backdrop, the reported plan by the FDA to impose a black box warning on COVID-19 vaccines is not merely misguided—it would constitute professional malfeasance that risks undermining one of the greatest public-health achievements of the past century.
No evidence
According to multiple reports, the proposal is being driven internally by Dr. Vinay Prasad, the rude, misguided FDA’s chief medical and scientific officer and director of the Center for Biologics Evaluation and Research (CBER), with the approval of Health and Human Services Secretary Robert F. Kennedy Jr., a long-time vaccine critic. The plan has shocked outside experts because, quite simply, there is no evidentiary basis for it.
Following a tsunami of outrage from the scientific and medical communities about the negative impacts on public health that such a move would cause, FDA Commissioner Marty Makary backed down, saying on December 15th that there were no plans for it at this time. Many FDA-watchers, including this author, are unconvinced.
What a Black Box Warning Is—and What It Is Not
A black-box warning is not a neutral informational update. It is the FDA’s most aggressive regulatory communication via product labeling, intended to alert clinicians and patients to risks so grave that they may outweigh a product’s benefits or require extreme restrictions on its use.
When a black box appears at the top of a drug label, it sends a blunt message: This product can kill you or cause devastating harm.
The FDA does not use this tool lightly—or at least, it is not supposed to. Black box warnings typically follow copious amounts of accumulated data, clear causal links, and extensive public review. They are often accompanied by advisory committee meetings, safety communications, and transparent analyses explaining why the warning is justified.
None of that appears to be happening here.
As Harvard regulatory expert Dr. Aaron Kesselheim has noted, black box decisions usually involve a discernible process: public notification, advisory committee review, and open discussion of the evidence. In this case, there has been no advisory committee, no publicly released analysis, and no explanation of what new data—if any—justify elevating COVID-19 vaccines into the FDA’s most dangerous category.
The Safety Record the FDA Is Ignoring
The irony is difficult to miss. COVID-19 vaccines are among the most intensively studied medical products ever deployed.
Before authorization, they were tested in randomized, placebo-controlled trials involving roughly 75,000 participants. After authorization, they were administered to hundreds of millions of Americans and more than 13 billion people worldwide, with safety monitored through multiple overlapping systems: clinical trials, active surveillance networks, national registries, and pharmacovigilance programs across more than 90 countries.
A recently published update confirmed the long-term safety of the mRNA COVID-19 vaccines:
In this national cohort study of 28 million individuals [in France], the results found no increased risk of 4-year all-cause mortality in individuals aged 18 to 59 years vaccinated against COVID-19, further supporting the safety of the mRNA vaccines that are widely used worldwide.
The results are unequivocal. Serious adverse events are rare. Catastrophic outcomes are rarer, almost nonexistent.
Risk must always be balanced against benefits. One modeling study estimated that in the first year alone, COVID-19 vaccines averted nearly 20 million deaths worldwide. In the United States, they dramatically reduced hospitalizations, intensive care admissions, and deaths across every adult age group. More recently, CDC data show that during the 2024–25 respiratory virus season, vaccinated children had a substantially lower risk of COVID-related emergency department and urgent-care visits.
Against this overwhelming benefit, what is the alleged risk that justifies a black box?
Myocarditis: A Known Risk, Already Addressed
The administration has repeatedly pointed to myocarditis—heart inflammation—as a concern. But myocarditis associated with mRNA COVID-19 vaccines is neither common nor often serious.
It was detected early, investigated intensively, and transparently communicated by the CDC and FDA years ago. The risk was found to be highest in adolescent and young adult males, typically after the second dose given at a short interval following the first. Most cases were mild and resolved quickly with conservative treatment. Critically, U.S. surveillance has found no confirmed myocarditis-related deaths or heart transplants linked to mRNA vaccination in adolescents or young adults. [link?]
Moreover, the risk has declined substantially as dosing intervals were lengthened—a change made precisely because the regulatory system was functioning as intended.
These facts are already reflected in current labeling. In May, the FDA expanded existing warnings in prescribing information for Pfizer and Moderna COVID vaccines to note that the observed risk of myocarditis and pericarditis has been highest in males aged 12 through 24.
That is how safety regulation is supposed to work: proportionate, evidence-based, and responsive. A black box warning would represent a quantum leap beyond that—suggesting risks comparable to opioids or teratogenic drugs—without any comparable evidence.
Claims Without Data: A Regulatory Red Flag
The most alarming aspect of the proposal may be how little information has been provided to justify it.
In a late-November memo to CBER staff, Dr. Prasad claimed that FDA scientists had “found that at least 10 children have died after and because of receiving COVID-19 vaccination.” No ages. No medical histories. No vaccine brands. No timelines. No causal analyses. No public data.
That is not how vaccine safety science works.
As Dr. Fiona Havers, a former CDC epidemiologist who resigned over political interference, has emphasized, vaccines—like all medical interventions—can be temporally associated with rare adverse events. Determining causality requires detailed clinical review, background rate comparisons, and transparent methods. None of that has been shared.
Fear-mongering, plain and simple
To raise the specter of pediatric deaths while withholding evidence is not caution. It is fear-mongering, which has become an alarmingly familiar trademark of Robert F. Kennedy, Jr.’s HHS agencies.
Even more troubling, these claims are being amplified in an environment in which anti-vaccine organizations are openly pressuring regulators. Earlier this month, Children’s Health Defense—the nonprofit formerly led by HHS Secretary Kennedy—filed a citizen petition urging the FDA to revoke COVID-19 vaccine licenses altogether, arguing they are “misbranded.” That claim has been repeatedly rejected by courts, scientists, and regulators.
Process Abandoned, Politics Ascendant
The FDA’s legitimacy rests on one core principle: Decisions are made through transparent, evidence-based processes insulated from political pressure.
That principle is now in jeopardy.
Dr. Prasad himself is a controversial figure, known long before joining the FDA for outspoken criticism of COVID-19 vaccines and public health measures. His tumultuous tenure—appointment, resignation under pressure, and rapid reinstatement—has raised serious concerns about independence and governance within the agency. He has asked subordinates who disagree with him to tender their resignations.
The result, as one former federal health official put it, is “death by a thousand cuts”: a steady drip-drip-drip of messaging that exaggerates vaccine risks, minimizes benefits, and erodes public trust. Claims that vaccines are riskier when given together, that the day-of-birth dose of Hepatitis B vaccine should be delayed, or that children receive “too many” vaccines with “dangerous ingredients,” directly contradict decades of immunology and epidemiology.
A black box warning would be yet another life-threatening cut.
The Predictable Consequences
We do not need to speculate about what will happen if COVID-19 vaccines receive a black box warning. We have decades of evidence on how such warnings affect behavior: They reduce prescribing and deter patients from being vaccinated. Sometimes they are appropriate; sometimes they overshoot, leading to unintended harm. In psychiatry, for example, poorly communicated warnings have been associated with reduced treatment and worse outcomes.
Applied to COVID-19 vaccines, the consequences would be stark. Uptake would fall. Hesitant parents would opt out. Clinicians would face legal and ethical uncertainty. And preventable hospitalizations and deaths would rise—especially among older adults, immunocompromised people, and unvaccinated children.
As Dr. Angela Rasmussen, a virologist and co-editor-in-chief of the journal Vaccine, has noted, a black box warning signals that a product is inherently dangerous. That message would be broadcast not only to U.S. patients, but globally—handing anti-vaccine movements a powerful new talking point, stamped with FDA authority.
A Warning About the FDA Itself
Most alarming of all is what this episode signals about the FDA’s future.
If black box warnings can be imposed without transparent data, without advisory committee review, and without clear causal evidence—based instead on ideological opposition to a product—then no vaccine, and no drug, is safe from politicized regulation.
That would mark a fundamental break with the consensus that built the FDA into a world-class drug regulator.
It is bitterly ironic that this assault is occurring under an administration that inherits Operation Warp Speed—an unprecedented scientific and logistical success that delivered safe, effective vaccines in record time. What was once touted, correctly, as a triumph of American innovation and regulation is now being discredited by the very government that once claimed credit for it.
The Ethical Failure
Public-health communication carries moral weight. Governments have an obligation to convey risks accurately, proportionately, and in context. To emphasize speculative harms while ignoring documented benefits is not neutrality—it is distortion. It violates the ethical duty to protect the public with honest, complete information.
Rare adverse events should be studied. Signals should be investigated. But the bar for a black box warning is—and must remain—extraordinarily high.
On the evidence available, that bar has not been met. Not remotely.
A Line That Must Not Be Crossed
If the FDA proceeds with a black box warning for COVID-19 vaccines without releasing its data, convening independent experts, and demonstrating a clear, causal, life-threatening risk that outweighs enormous benefits, it will not be acting as a scientific regulator. It will be acting as a political instrument.
The cost will not be measured in headlines or lawsuits. It will be measured in missed vaccinations, overflowing hospitals, an increased burden of long COVID, and lives lost needlessly.
The real hazard is not the vaccines, but the warning itself.
