MMR Vaccine Not Linked To Autism, Even In High Risk Children

New findings published in a recent edition of JAMA show that there is not a common link between the MMR vaccine and autism, even when used among high-risk children.

A large-scale study that looked at 95,000 children with older siblings determined that the MMR vaccine had no influence on the risk of autism spectrum disorders (ASD) regardless of whether or not the older sibling had ASD.

Most of the research conducted over the past 15 years has come to a similar conclusion, despite the fact that parents worry that an MMR vaccine could trigger the symptoms of an ASD in their child.

"Consistent with studies in other populations, we observed no association between MMR vaccination and increased ASD risk among privately insured children. We also found no evidence that receipt of either [one] or [two] doses of MMR vaccination was associated with an increased risk of ASD among children who had older siblings with ASD. As the prevalence of diagnosed ASD increases, so does the number of children who have siblings diagnosed with ASD, a group of children who are particularly important as they were undervaccinated in our observations as well as in previous reports," the authors wrote.

Out of 95,727 children in the study sample, 2.01 percent had older siblings with an ASD. Yet overall, only 1.04 percent of the children included in the cohort received an ASD diagnosis during the follow up period. For those with older siblings who had ASD, 6.9 percent were diagnosed with the condition when compared to about 0.9 percent of children whose siblings did not have ASD

The MMR vaccination rate for children with unaffected siblings was 84 percent at 2 years of age and 92 percent in 5-year-olds, compared with 73 percent at 2 years and 86 and 5 in the group with affected siblings. The analysis did not find a link between ASD diagnosis and MMR vaccine.