A comprehensive study involving over 2.5 million US children finds no evidence linking the MMR vaccine to autism, as measles cases hit 35-year high and vaccine debates intensify.
A new study involving more than 2.5 million children in the United States has found no evidence that receiving the measles, mumps and rubella vaccine before the age of 2 increases the risk of autism. Researchers at the University of Washington said their findings add to a long-running body of work showing no causal link between the MMR jab and autism, reinforcing what public health agencies have said for years.
The timing of the study matters. Measles cases in the US have reached a 35-year high, while childhood vaccination rates have been slipping since before the pandemic. Against that backdrop, federal health messaging has become increasingly muddled. Health Secretary Robert F. Kennedy Jr., who has in the past promoted unapproved measles treatments, told CNN that people should get the MMR vaccine to protect against the virus, yet he also repeated longstanding doubts about vaccine safety when discussing autism and clashed with anchor Dana Bash over the issue.
The controversy is tied in part to a 1998 paper by Andrew Wakefield, which suggested a link between vaccination and developmental regression in children. That study was later retracted after flawed methods were exposed, and the British doctor’s medical licence was revoked. The American Academy of Pediatrics has said the paper became a classic example of how misinformation can spread and persist, even after being discredited.
The broader scientific record points the other way. In December 2025, the World Health Organisation’s Global Advisory Committee on Vaccine Safety reviewed 31 studies published over 15 years and concluded there was no causal connection between vaccines and autism spectrum disorder, including for vaccines containing aluminium adjuvants. The CDC also says reviews by the Institute of Medicine and the Agency for Healthcare Research and Quality found no association between the MMR vaccine and autism, though the agency’s autism information page was altered in November to suggest studies had not ruled out a possible link, a change that drew criticism from paediatric specialists.
Disclaimer: This content is for informational purposes only and is not intended to be a substitute for professional medical judgment, advice, diagnosis, or treatment.
