The Plain Truth About Vaccines and Autism
We respect families not by perpetuating recycled myths, but by pursuing real science and better care.
For more than two decades, scientists have studied whether vaccines cause autism. The answer has been consistent: they don’t. But parents’ concerns – and disinformation – linger, and every moment spent disproving it detracts from real progress toward understanding autism, helping families, and protecting people from preventable health threats.
Last week, The New York Times published an exhaustive review of the science on vaccines and autism, exposing the playbook of how deceptive studies are used to attempt to falsely suggest a link. This is part of the playbook to sow distrust in vaccines and science: amplify flawed research or use a kernel of truth to bolster false, sweeping claims.
Health Secretary Robert F. Kennedy Jr. knows this playbook well. He built a following and lucrative career by promoting his anti-vaccine beliefs – beliefs that reportedly contributed to the ouster of CDC Director Susan Monarez this week after less than a month in the job. Her dismissal reportedly stemmed from her objection to potential changes to the childhood vaccine schedule based on dangerous falsehoods. Within hours of the Monarez news, four other high-level CDC leaders with deep expertise in immunization, infectious diseases, and other health threats, resigned. This represents the loss of 100 years of public health expertise, crucial agency leadership, and is an unprecedented assault on our health protection agency.
This isn’t just about words, committees, and personnel appointments. For 60 years, CDC has used the best data and the best practical experience to recommend which vaccines doctors should offer to patients. For 30 years, the Vaccines For Children (VCF) program – a bipartisan success story – has protected generations of kids. By one estimate, this program has prevented more than 500 million cases of illness, more than 30 million hospitalizations, and more than a million deaths, with net economic savings of more than $500 billion in direct costs and $2.7 trillion in societal costs. The program narrowed or eliminated gaps in access, making these vaccines available to all. That progress is now very much at risk. Half of American kids get their vaccines through the VFC. If the Advisory Committee for Immunization Practices – now packed with people who have unscientific and misguided views on vaccines – doesn’t recommend a vaccine, half of American kids may lose access to those free vaccination.
What we know
The claim that vaccines cause autism has been tested – again and again – and found to be false.
A comprehensive meta-analysis of more than 1.2 million children found no link between vaccines – including MMR, thimerosal, or mercury – and autism. Odds ratios hovered around 1.0, the scientific equivalent of no effect.
A Danish study of 657,000 children found no increased autism risk after MMR vaccination, even among children with a family history of autism.
U.S. data on cumulative antigen exposure showed no association with autism. The odds ratio per unit increase in antigen exposure was essentially 1.0.
Studies from Japan, where vaccine schedules differ, also found no connection between autism and either the MMR vaccine or thimerosal.
Systematic reviews reinforce these findings. The American Academy of Pediatrics states unequivocally: there is no link between vaccines and autism – or with sudden infant death syndrome, immune dysfunction, diabetes, or neurologic disorders.
What about other adverse events?
Some claim vaccines cause autoimmune or allergic conditions. Large-scale studies indicate otherwise:
A Danish study of 1.2 million children found no link between aluminum in vaccines and chronic disease, autoimmune illness, or developmental disorders.
A meta-analysis found no increased risk of allergies after vaccines. In fact, some vaccines reduced risk: measles vaccination lowered asthma and eczema rates.
Autoimmune disease risks is not present with any currently used vaccines. Prior formulations did rarely cause problem, such as a rare disease (Guillain-Barré) after the swine flu vaccination in 1976. This is why public health specialists carefully track the possibility of such reactions to current vaccines; no associations have been found.
Giving multiple vaccines together is safe. Decades of monitoring have found no harmful “cumulative” or “interactive” effects.
The bottom line
Every hour spent fighting disproven claims is an hour not spent on real science. Autism has complex roots – genetic, developmental, and environmental. Chasing false links wastes time, resources, and trust.
Parents have valid concerns that shouldn’t be dismissed, and it’s incumbent on the medical community to take the time to listen respectfully and answer questions. Parents deserve honest answers, based on evidence. They also deserve support. Autism research should focus on understanding brain development, improving early detection, and expanding services that help children thrive.
Vaccines save lives. There is no credible evidence that they cause autism. Pretending otherwise hurts kids twice – by undermining trust in vaccines, and by distracting from the urgent need to understand and address autism itself. We respect families affected by autism not by perpetuating recycled myths, but by pursuing real science and better care.
Dr. Tom Frieden is author of The Formula for Better Health: How to Save Millions of Lives – Including Your Own.
The book draws on Frieden's four decades leading life-saving programs in the U.S. and globally. Frieden led New York City's control of multidrug-resistant tuberculosis, supported India's efforts that prevented more than 3 million tuberculosis deaths, and led efforts that reduced smoking in NYC.
As Director of the CDC (2009-2017), he led the agency's response that ended the Ebola epidemic. Dr. Frieden is President and CEO of Resolve to Save Lives, partnering locally and globally to find and scale solutions to the world's deadliest health threats.
Named one of TIME's 100 Most Influential People, he has published more than 300 scientific articles on improving health. His experience is, for the first time, translated into practical approaches for community and personal health in The Formula for Better Health.