Peter Hotez Continues to Avoid Facts on Vaccines and Autism

Not all vaccines have been tested for association with autism, and association does not test causality.

In his recent comments published by MedPage Today, Dr. Peter Hotez once again repeated a series of patently false claims about the relationship between vaccines and autism—claims that collapse under even modest scrutiny. While such proclamations may serve institutional interests or protect careers, they betray both scientific integrity and the public trust. It is time to confront these claims directly, because those who assert that “the science is settled” on this issue are neither entitled to that conclusion, nor in possession of the evidence required to sustain it.

Hotez states, without caveat, that “we have now massive evidence showing there’s no link between vaccines and autism.” He further claims that autism is purely a consequence of “early fetal brain development through the action of autism genes,” thereby dismissing the role of environmental factors beyond the first trimester of pregnancy—including vaccines administered postnatally. Finally, he warns that the current Secretary of Health and Human Services, Robert F. Kennedy Jr., poses a danger to public health by re-examining the vaccine-autism connection and exploring non-vaccine-based interventions for conditions like measles. These assertions are not only wrong—they are dangerous in the very way Hotez accuses others of being.

Let us begin with the central pillar of Hotez’s argument: that “massive evidence” has disproven any causal link between vaccines and autism. This is categorically false. The evidence he refers to is narrow in scope, methodologically inadequate, and heavily compromised by conflicts of interest. The studies typically cited in support of this claim focus almost exclusively on one vaccine: the MMR. They avoid vaccines containing aluminum adjuvants. They avoid addressing cumulative exposure across the entire CDC-recommended schedule. They generally rely on retrospective designs with incomplete or manipulated data, lack long-term neurodevelopmental follow-up, and rarely—if ever—include fully unvaccinated controls.

Even if the MMR studies were flawless—and they are not—they would say nothing definitive about the myriad other vaccines routinely administered to infants and toddlers during sensitive windows of brain development. For many vaccines, no autism safety studies exist at all. Not a single study on IPV, PCV13, Rotavirus, Influenza, or Hib vaccines has evaluated autism outcomes, and yet these are given within the first six months of life. The Hepatitis B vaccine, administered on the day of birth, has been associated with increased autism risk in at least two independent studies. That these data are ignored or dismissed by public health officials like Hotez reveals not scientific confidence, but systematic denial.

The claim that autism is caused solely by genetic changes in fetal brain development is equally antiquated. Modern science understands autism as a complex systems disorder—a result of gene-environment interactions, immune activation, mitochondrial dysfunction, oxidative stress, epigenetic modulation, and microbiome disruption. Identical twin studies consistently show that genetic concordance is well below 100%, often closer to 60–70%, indicating substantial environmental contribution - even without considering genetic x environment interaction. Prenatal factors, such as maternal infections, environmental toxicants, and immune dysregulation, are known contributors. So why would CDC insist on vaccinating pregnant women with thimerosal-containing vaccines? Those risks do nothing to rule out postnatal immune challenges, including vaccination, particularly when administered during periods of rapid synaptogenesis and myelination.

A large body of research has uncovered mechanistic plausibility linking vaccination to neurodevelopmental disorders. Aluminum adjuvants, used in several pediatric vaccines, are known neurotoxins with the capacity to activate microglia, alter dendritic spine formation, and persist in the brain for years. Studies have demonstrated that aluminum nanoparticles injected into animals can cause behavioral abnormalities consistent with autism-like phenotypes. Yet this evidence is neither included in risk assessments nor publicly acknowledged by defenders of the vaccine schedule.

In 2014, CDC senior scientist Dr. William Thompson came forward as a whistleblower, revealing that the CDC omitted statistically significant findings from its own study showing that African-American boys vaccinated with MMR before 36 months had a higher risk of autism. Thompson provided thousands of pages of internal documents confirming that the data had been manipulated and key evidence destroyed. No congressional hearings followed. No reanalysis was ordered. No institutional accountability occurred. Instead, the medical establishment pretended the revelations didn’t exist—just as it pretends that vaccine safety science is settled.

Injury compensation systems provide further proof that the vaccine-autism question remains open. The National Vaccine Injury Compensation Program (NVICP) has paid out billions of dollars to families of vaccine-injured children, including some cases involving encephalopathy with subsequent developmental regression. In 2008, the case of Hannah Poling—a child with a mitochondrial disorder who developed autism-like symptoms after receiving multiple vaccines in one day—was conceded by the federal government. The message was clear: certain children are more vulnerable. Yet the public narrative remained unchanged, as though the exception proved the rule.

The truth is that there has never been a prospective, vaccinated vs. unvaccinated study powered to detect differences in autism rates. No one has attempted such a study using modern epidemiological methods while controlling for genetic predisposition, mitochondrial dysfunction, immune status, or adjuvant load. The few retrospective studies comparing fully unvaccinated children to vaccinated ones—including several published by independent researchers—do find significantly higher rates of neurodevelopmental disorders among vaccinated children. These studies are ignored, dismissed without review, or attacked ad hominem—not because of their quality, but because of their implications.

Hotez also takes aim at alternative interventions for measles, falsely equating them with quackery. In doing so, he either reveals ignorance or purposeful distortion. Vitamin A supplementation has long been endorsed by the World Health Organization for use in children with measles, especially in regions with high mortality. It reduces death rates by over 50%. Clarithromycin, while not antiviral, may be used to treat secondary bacterial infections that frequently complicate measles. Budesonide is sometimes used off-label to manage inflammatory respiratory complications. These treatments are not replacements for vaccines—but neither should they be dismissed as ineffective, especially when used in therapeutic contexts.

Finally, Hotez warns that efforts by RFK Jr. to re-evaluate vaccine safety may unravel the “vaccine ecosystem.” But what kind of ecosystem requires censorship, financial immunity, legal shields, manipulated data, captured regulators, and coerced participation to survive? If the ecosystem unravels, it is because it was built on a foundation of propaganda, not evidence. Real science does not fear scrutiny. Real science invites challenge, transparency, replication, and accountability.

No scientist—no matter how credentialed—is entitled to make definitive claims on questions that remain scientifically unresolved. To say "vaccines do not cause autism" when most vaccines have never been studied for such an effect is not just dishonest. It is malpractice. It is the rhetorical equivalent of claiming a medication is safe for every organ system when only the kidneys have been tested. It is a lie wrapped in a lab coat, sold as certainty.

Those harmed by this lie—families who lost their children’s futures to vaccine injury—have been silenced, marginalized, and ridiculed. Their experiences have been recast as delusion, their questions as conspiracy. They have been told, again and again, that their observations mean nothing, that their children’s regression was coincidence, and that they must accept this verdict because “the science is settled.”

But the science is not settled. It was never settled. It was substituted—replaced with shallow, agenda-driven studies, reinforced by slogans, and protected by a fortress of institutional denial. That fortress is now crumbling—not because of ignorance, but because people are waking up. They are reading the studies. They are asking questions. They are finding the courage to speak, despite the consequences.

Peter Hotez can continue to pretend that the evidence is overwhelming. He can continue to dismiss dissent and repeat his mantras. But he cannot erase the facts. The truth is immune to repetition, and it does not require permission to be known.

See also: