HealthDay News — A large study found no evidence that the measles-mumps-rubella (MMR) vaccine raises the risk of autism, even among children who are at increased genetic risk. The research was published in JAMA.
The new findings are based on insurance records for 95,727 U.S. children with an older brother or sister; 2% had an older sibling with an autism spectrum disorder.
The researchers found that of the children with an affected sibling, 6.9% had an autism spectrum disorder themselves, compared to 0.9% of other children. There was no evidence, though, that the MMR vaccination raised the risk of autism in either group of children. Among children with an affected sibling, those who’d received one MMR dose by age 2 were actually one-quarter less likely to be diagnosed with an autism spectrum disorder. The odds were even lower among those who’d received two doses by age 5.
“Research has shown that parents of kids with autism spectrum disorders are more likely to delay vaccinating their younger children,” Bryan King, MD, an autism researcher at the University of Washington in Seattle, told HealthDay. “Basically, they wait until the developmental dust has settled, and it looks like their child will be unaffected,” he said. King wrote an editorial published with the study.