Is the MMR Vaccine Safe?

Paul A. Offit, MD, addresses the history of concerns about the safety of MMR vaccine and how we know the MMR vaccine is safe and effective.


Is the MMR vaccine safe?

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

Probably one of the more common questions we get asked here at the center is, “Is the MMR vaccine safe?” MMR stands for measles, mumps, rubella. The shorter answer is, yes. But where this comes from — where the fear comes from — is that there was a paper published in a medical journal called The Lancet in 1998 claiming that that vaccine, the MMR vaccine, increased one’s risk of autism. It was really just a case series; it was a report of 12 children, eight of whom had autism within a month of receiving that vaccine. So, what you could argue is that the best thing that that paper might’ve done was it raised the question, “Could MMR vaccine cause autism?” Because certainly some parents could say, reasonably, “Look, my child was fine, they got this MMR vaccine, and now they’re not fine. Now they have autism. They have signs and symptoms of autism. Could the vaccine have done that?”

The good news is that’s a scientific question; that’s an answerable questions. It can be answered in a scientific venue, and it has been. There have now been 18 studies, done in seven different countries, on three different continents, involving hundreds of thousands of children, and costing tens of millions of dollars, to look at groups of children who either did or didn’t get the MMR vaccine, making sure that those two groups were alike in all other aspects — healthcare-seeking behavior, socioeconomic background, medical background — so you could isolate the effect of that one variable: receipt of MMR vaccine. And study after study after study, now 18 studies have shown that you’re at no greater risk of getting autism if you got the MMR vaccine or if you didn’t.

So, I think you can now say that that question has been asked and answered. And certainly now where we’re seeing more and more cases of measles because people … some parents are choosing not to vaccinate their children, it’s become more important than ever to make sure that you get the MMR vaccine because measles is a bad disease. I mean before there was a measles vaccine in this country in the 1960s, every year about 3 million people would get measles, mostly children less than 15 years of age, 48,000 would be hospitalized, and 500 would die — die when measles virus infected the lungs and caused pneumonia, or die when measles virus infected the brain and caused encephalitis. So, it’s an important vaccine to get, and although I think parents should be skeptical of anything they put into their bodies, including vaccines, I think parents can be reassured that the MMR vaccine is safe.

Thank you.

Related Centers and Programs: Vaccine Education Center

Last Reviewed on Jan 27, 2020