Can Vaccines Cause Autism?

As a parent, you may be concerned about the increasing prevalence of autism and no known cause for the condition. Vaccines do not cause autism. Over 100 different studies have looked for a possible connection between vaccines and autism, and none have found evidence of a link. For more information about potential causes of autism, check out the Autism Science Foundation.

The myth surrounding vaccines and autism has shifted over the years. In 1998, a British researcher, Andrew Wakefield, suggested that the measles, mumps, and rubella (MMR) vaccine might cause autism. To determine whether Wakefield’s hypothesis was correct, researchers performed a series of studies comparing hundreds of thousands of children who had received the MMR vaccine with hundreds of thousands who had never received the vaccine. They found that the risk of autism was the same in both groups and that the MMR vaccine did not cause autism.

In 2010, Wakefield’s study suggesting that the MMR vaccine might cause autism was fully retracted by its publisher. The study was found to be scientifically unsound because Wakefield had manipulated and falsified his data. Since then, Wakefield’s medical license has been revoked.

Once Wakefield’s theory was debunked, a new myth emerged, claiming that the ingredient thimerosal caused autism. Thimerosal is a mercury-containing preservative that was used in vaccines to prevent contamination. Due to public pressure, thimerosal was removed from children’s vaccines in 1999, and several studies since have shown no link between thimerosal and autism.

The latest myth claims that autism is caused by children receiving too many vaccines too soon and being exposed to too many immunological components. Several facts make this highly unlikely:

  • As discussed earlier (“Can I Space Out My Child’s Shots?”), although the number of vaccines has increased during the past century, the number of immunological components in vaccines has decreased.

  • The immunological challenge from vaccines is tiny compared to what babies encounter every day.

  • Children have an enormous capacity to respond to immunological challenges because humans have the capability to make between 1 billion and 100 billion different types of antibodies.

Given the number of immunological components contained in vaccines, a conservative estimate would be that babies have the capacity to respond to about 100,000 different vaccines at once.

Amy, Southern Oregon

"I breastfed both of my daughters for nearly two years each and vaccinated my children on a regular schedule until the year 2010, when my oldest daughter was diagnosed with Asperger’s syndrome, a form of autism. I had read articles in the media and heard from some of my friends who did not vaccinate their children that vaccinations could have caused this 'disorder' in my daughter.

Around the same time I was researching vaccinations, the actress Jenny McCarthy was widely promoting her book about her son, her choice not to vaccinate, and autism. I was convinced not to vaccinate my daughters anymore.

We were only about two weeks late with their next vaccination appointment when I reconnected with my friend Sabrina. She had lost her son, Dylan, to meningitis, a vaccine-preventable disease. I met with my doctor in Ashland, who was willing to have a long discussion with me about the importance of being fully immunized. Both of my daughters have continued to stay up to date with their vaccines to this day.

As a mother who has a daughter with autism, I don’t believe that there is enough concrete information to suggest that vaccines could have caused my daughter to have autism. When she was born, before any vaccinations, she would shake her tiny hands in front of her mouth. This was unusual compared to the other babies we were around. This has now evolved into the stemming that she does, which is an indicator for autism and autism spectrum disorders.

I urge everyone to vaccinate their children. I don’t ever want to have to say ” good-bye to my babies and forever regret not doing something that could have saved their lives."