JAMA Network | JAMA | Autism Occurrence by MMR Vaccine Status Among US Children With Older Siblings With and Without Autism

http://jama.jamanetwork.com/article.aspx?articleid=2275444

receipt of the MMR vaccine was not associated with increased risk of ASD, regardless of whether older siblings had ASD. These findings indicate no harmful association between MMR vaccine receipt and ASD even among children already at higher risk for ASD.

---Steve