No MMR-ASD link in high-risk children

Nurses can reassure parents that the measles, mumps and rubella (MMR) vaccine does not seem to increase the risk of autism-spectrum disorders (ASD) even among high-risk children.

The study enrolled 95,727 children with older siblings. Of these, 1.04% were diagnosed with ASD and 2.01% had an older sibling with ASD. The MMR vaccine did not significantly increase ASD risk, regardless of whether their older siblings had ASD. Among children with an older sibling with ASD, the relative risks of ASD in those who received one or two MMR doses were 0.76 and 0.56 respectively in comparison to unvaccinated children. Among those whose older sibling did not have ASD, the relative risks were 0.91 and 1.12, respectively.