"Autism Occurrence by MMRVaccine Status Among US Children With Older Siblings With and Without Autism", a new important study discrediting the correlation between MMR Vaccine and autism, published at the end of April on the Journal of the American Medical Association (JAMA).

Summary of the article

Two doses of measles-mumps-rubella (MMR) vaccine are currently recommended for children in the United States: the first at age 12 to 15 months and the second at age 4 to 6 years. Although a substantial body of research over the last 15 years has found no link between the MMR vaccine and autism spectrum disorders (ASD), parents and others continue to associate the vaccine with ASD.

Parents cite vaccinations, especially MMR, as a cause of ASD 6 and have deferred or refused vaccinations for their children as a result. Lower vaccination levels threaten public health by reducing both individual and herd immunity and have been associated with several recent outbreaks of measles, with most cases occurring among unvaccinated individuals.

Families with a child affected by ASD may be particularly concerned about reports linking MMR and ASD. This belief, combined with knowing that younger siblings of children with ASD are already at higher genetic risk for ASD compared with the general population, might prompt these parents to avoid vaccinating their younger children. Thus, we set out to report on ASD occurrence by MMR vaccine status in a large sample of US children having older siblings with ASD and to compare findings with those among children who have older siblings without ASD.

A retrospective cohort study using an administrative claims database associated with a large commercial health plan. Participants included children continuously enrolled in the health plan from birth to at least 5 years of age during 2001-2012 who also had an older sibling continuously enrolled for at least 6 months between 1997 and 2012.

MMR vaccine receipt (0, 1, 2 doses) between birth and 5 years of age. ASD status defined as 2 claims with a diagnosis code in any position for autistic disorder or other specified pervasive developmental disorder (PDD) including Asperger syndrome, or unspecified PDD.

In this large sample of privately insured children with older siblings, 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.

Authors: Anjali Jain, Jaclyn Marshall, Ami Buikema, Tim Bancroft, Jonathan P. Kelly, Craig J. Newschaffer

RELATED CONTENTS: