A large-scale study was not able to find a link between the common MMR vaccine and autism, even among high-risk children.
The recent study looked at about 95,000 children who had older siblings and determined the MMR vaccine had no influence on risk of autism spectrum disorders (ASD) regardless of whether or not the older sibling had ASD, the JAMA Network Journals reported.
Most research conducted over the past 15 years has come to the same conclusion, but many parents still worry the MMR vaccine can trigger autism in their children. This belief could cause parents to avoid the vaccination, especially if they believe their child has a high risk of ASD.
Out of the 95,727 children included in the study, 2.01 percent had an older sibling with ASD. Overall, 1.04 percent of children included in the cohort received an ASD diagnosis during the follow up period; among those who had an older sibling with ASD, 6.9 percent were diagnosed with the conditions, compared to only 0.9 percent of children who's sibling 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.
"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.
The findings were published in a recent edition of JAMA.
