No Link Between Vaccines and Autism, Large Study Confirms

Vaccines and autism were not associated in large analysis of studies

/ Author:  / Reviewed by: Joseph V. Madia, MD Beth Bolt, RPh

(RxWiki News) Vaccines have prevented millions of illnesses, yet some uneasiness about their safety persists for some parents. One of the biggest concerns has been shot down again.

A recent large study concluded that there was no link between vaccines and autism based on the various studies looking at this question.

The fears that vaccines and autism might be linked have been partly responsible for drops in immunizations, including for the measles-mumps-rubella (MMR) vaccine.

This year is on track to see the highest number of measles cases in nearly two decades, and several mumps outbreaks are occurring at college campuses.

"Discuss vaccinations with your child's pediatrician."

This study, led by Luke Taylor, of the Whiteley-Martin Research Centre at The University of Sydney in Australia, analyzed the data from studies about vaccines and any possible autism link.

Taylor and colleagues searched four research databases for all studies through 2014 dealing with vaccines and autism.

They identified five "cohort" studies, involving 1.26 million children, which followed a group of children who did or did not receive vaccines to see what their longer-term outcomes were.

They also identified five "case-control" studies involving 9,920 children. These studies compared children with autism to children without autism and looked at their vaccination histories.

The combined data from the five cohort studies showed no link between vaccinations and autism or any other autism spectrum disorder.

The data also did not show a link between autism spectrum disorders and either the MMR vaccine, thimerosal or mercury.

Thimerosal is an ethylmercury-containing preservative that was previously used in MMR vaccines.

Similarly, the data from the five case-control studies showed no increased risk for autism spectrum disorders among children who received the MMR or who were exposed to thimerosal or mercury.

"Findings of this meta-analysis suggest that vaccinations are not associated with the development of autism or autism spectrum disorder," the authors concluded.

"Furthermore, the components of the vaccines (thimerosal or mercury) or multiple vaccines (MMR) are not associated with the development of autism or autism spectrum disorder," they wrote.

This study was published April 24 in the journal Vaccine. The authors reported no conflicts of interest.

Review Date: 
May 20, 2014
Last Updated:
May 20, 2014