HealthDay News — Yet another study finds no evidence that the measles-mumps-rubella vaccine raises the risk of autism — even among children who are at increased genetic risk, study findings indicate.
“Despite research showing no link between the measles-mumps-rubella (MMR) vaccine and autism spectrum disorders (ASD), beliefs that the vaccine causes autism persist, leading to lower vaccination levels,” noted Anjali Jain, MD, of The Lewin Group in Falls Church, Virginia, and colleagues in the Journal of the American Medical Association.
“Parents who already have a child with ASD may be especially wary of vaccinations.”
To report ASD occurrence by MMR vaccine status, the investigators conducted a retrospective cohort study an administrative claims database associated with a large commercial health program. Of the 95,727 children included in the study, 2% had an older sibling with an autism spectrum disorder.
Of the children with an affected sibling, 6.9% had an autism spectrum disorder themselves, compared with 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 2 years of age 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 5 years of age.
“These findings indicate no harmful association between MMR vaccine receipt and ASD even among children already at higher risk for ASD,” concluded the investigators.