No Link Between MMR Vaccine and Autism, Study Finds

A national retrospective cohort study of more than 2.5 million children found no association between receiving the measles, mumps, and rubella (MMR) vaccine before age 2 years and having an autism diagnosis. 

“These results reinforce existing evidence supporting the safety of MMR vaccination,” wrote the authors, from the University of Washington. 

Some people worry that MMR vaccines cause autism, despite a lack of evidence supporting this theory. This paper is the latest to examine the MMR vaccine and autism by looking at the timing of the vaccine. 

Using the Cosmos electronic health record database, researchers looked at the records of more than 2.5 million children who had linked parent information from January 2015 through December 2024. The scientists followed the children until age 8 or their last doctor’s appointment before the study end date. 

Receiving the first MMR vaccine dose from ages 11.5 to 24 months was not associated with an increased likelihood of having an autism diagnosis. 

Kennedy acknowledges efficacy of MMR vaccine

It’s been a record-breaking year in the United States for measles, with the Centers for Disease Control and Prevention (CDC) reporting 2,371 cases this year, with 93% of these infections occurring in unvaccinated people. This is the highest number of measles cases since 1991.

In an interview with CNN’s Dana Bash yesterday, Secretary of Health and Human Services Robert F. Kennedy Jr. said he is not responsible for the ongoing measles outbreak, despite years of saying childhood vaccines cause autism. “I’ve never questioned the efficacy of the MMR vaccine,” he said. 

Kennedy also encouraged parents to vaccinate their children. “A measles vaccine is effective,” he said. “It stops measles in about 97% of the cases.”