Do Vaccines Cause Autism?

Paul A. Offit, MD, addresses concerns about vaccines and autism, describing the origin and nature of the concerns and the numerous scientific studies that have addressed them.


Do vaccines cause autism?

Paul Offit, MD: Hi, my name is Paul Offit. I’m talking to you today from the Vaccine Education Center at the Children’s Hospital of Philadelphia.

I think probably one of the most common concerns parents have about vaccines is, do they cause autism? Certainly, very easy to find that contention on the internet and in chat rooms, so it can be scary. And I think from the parents’ stand point, they argue this, “Look, my child was fine, they got a vaccine, now they've developed signs and symptoms of autism. Could the vaccine have done it?”

Well, the good news is that’s an answerable question. And it’s really been in three different areas that this issue has been raised. One is the concern that the combination measles-mumps-rubella, or MMR, vaccine caused autism. The second is the notion that there was an ethyl-mercury containing preservative that was in a number of vaccines, now it’s only in some multi-dose vials of influenza vaccine, called thimerosal. And the third sort of concern is that children are just getting too many vaccines too soon, that that’s somehow weakening, or overwhelming, or perturbing their immune system. Well, these are studiable questions; you can answer this question. So, for example in the case of measles, mumps and rubella, there now have been 18 studies done in seven different countries, on three different continents, involving hundreds of thousands of children who either did or didn’t get the MMR vaccine, making sure that those two groups are otherwise similar with regard to their healthcare-seeking behavior, their socioeconomic background, their medical background, and again, and again, and again those studies all found the same thing — that the MMR vaccine did not cause autism, and that’s been true also for these other two concerns.

The good news is I think most parents get this. I think most parents believe these studies because a recent study by the Autism Science Foundation found that about 85% of parents of children with autism now are comfortable that vaccines weren’t the cause.

Thank you.

Related Centers and Programs: Vaccine Education Center

Last Reviewed on Mar 26, 2020