A massive U.S. study involving 2.5 MILLION children has found no link between the MMR vaccine and autism.
As measles cases surge across the United States, new research published in The Pediatric Infectious Disease Journal adds powerful evidence against one of the most persistent myths in medicine.
Researchers led by a physician at UW Medicine analyzed health records from 2,560,035 American children, comparing those who received their first measles, mumps, and rubella (MMR) vaccine before age 2 with those who had not yet received it.
The children were followed through age 8, and the findings were clear: MMR vaccination was not associated with an increased risk of autism.
To strengthen their findings, researchers also examined a routine pneumococcal vaccine booster and found similarly reassuring results.
The misconception linking MMR vaccines to autism originated with a controversial 1998 study that was later retracted. Decades of research involving millions of children have repeatedly failed to establish any causal connection.
Meanwhile, measles is making a troubling comeback. According to the CDC, the United States had recorded 4,588 confirmed measles cases in 2026 as of October 22, highlighting the importance of vaccination against this highly contagious disease.
While no observational study can eliminate every possible source of bias, this enormous investigation adds to the overwhelming scientific evidence that the MMR vaccine does not cause autism.
Source: Burstain et al. (2026), The Pediatric Infectious Disease Journal. DOI: 10.1097/INF.0000000000005349. CDC Measles Surveillance (2026).