Vaccines and autism
Decades of large-scale epidemiological research across multiple countries have found no causal link between vaccines and autism spectrum disorder. The original 1998 study that sparked the controversy was retracted after being exposed as deliberate scientific fraud.
What we know
The claim that vaccines cause autism originated primarily from a 1998 Lancet paper by Andrew Wakefield, which was later fully retracted after investigations revealed that Wakefield had manipulated patient data, had undisclosed financial conflicts of interest, and committed ethical violations in how children were studied. The British Medical Journal published an investigation in 2011 confirming the paper was fraudulent.
Since the retraction, numerous large independent studies involving millions of children across Europe, North America, and Asia have consistently found no association between any vaccine — including the MMR vaccine — and autism spectrum disorder. In December 2025, WHO's Global Advisory Committee on Vaccine Safety (GACVS) reviewed 31 primary research studies published between 2010 and 2025 and reaffirmed its conclusion that vaccines do not cause autism.
A 2014 review by the U.S. Agency for Healthcare Research and Quality and an independent 2012 Institute of Medicine report both concluded that evidence was insufficient to support a causal relationship between autism and DTaP, HepB, Hib, IPV, and PCV vaccines. For the MMR vaccine specifically, the 2012 IOM report found high-strength evidence of no association based on observational studies.
The misperception persists partly because autism symptoms often become apparent around the same ages children receive routine vaccinations — a correlation that reflects developmental timing, not causation. Scientific and medical consensus globally, including from WHO, the U.S. CDC, the European Medicines Agency, and national health authorities, affirms that vaccines do not cause autism.
Common claims
- The MMR vaccine causes autismNot supported by evidence — based on a retracted, fraudulent study
- Thimerosal (mercury) in vaccines causes autismNot supported by evidence — multiple studies show no association
- Aluminum adjuvants in vaccines cause autismNot supported by evidence — large cohort studies show no association
- The original Wakefield study proved a vaccine-autism linkFalse — the study was retracted and declared fraudulent
Evidence hierarchy
All sources
- WHO GACVS: No link between vaccines and autism (December 2025)World Health Organization · 2025
- Wakefield's article linking MMR vaccine and autism was fraudulentThe BMJ · 2011
- The MMR vaccine and autism: Sensation, refutation, retraction and fraudIndian Journal of Psychiatry / PubMed Central · 2011
- Autism and Vaccines — CDCCenters for Disease Control and Prevention · 2025
- WHO MMR Vaccines and Autism — GACVSWorld Health Organization · 2003