MMR Vaccine and Autism: Busting the Myth with the Evidence

It's one of the most common questions parents ask us, and it's a fair one: you want to be sure that everything you do for your child is safe. So here is the short answer, and then the evidence behind it.

The MMR vaccine does not cause autism. This has been studied in millions of children, in many countries, over more than 25 years. The American Academy of Pediatrics (AAP) and every major medical organization agree.

Where the myth came from

In 1998, a British doctor named Andrew Wakefield published a study of just 12 children in The Lancet suggesting a link between the MMR vaccine and autism. Investigations later found the study was seriously flawed and dishonest. The Lancet fully retracted the paper in 2010, and Wakefield lost his medical license. But the fear it created has lasted much longer than the study did.

What the research shows

• A study of more than 650,000 children in Denmark, published in 2019, found no increased risk of autism after MMR, including in children considered at higher risk because they had a sibling with autism.
• A U.S. study of about 95,000 children with older siblings, published in JAMA in 2015, found no link, even among children whose older brother or sister had autism.
• A Cochrane review of 138 studies found no evidence of an association between the MMR vaccine and autism.

Why the timing can feel connected

The first MMR dose is given at 12 to 15 months, which is about the same age parents often first notice signs of autism. When two things happen around the same time, it's natural to wonder whether one caused the other. But research suggests that autism begins developing much earlier, before birth, and that genetics play a large role.

Is it safer to space out or split the MMR?

No. Separate single vaccines for measles, mumps, and rubella aren't available in the United States, and delaying the MMR only leaves your child unprotected for longer. Measles is one of the most contagious diseases there is: up to 9 out of 10 unvaccinated people close to someone with measles will catch it. It can cause pneumonia, brain swelling, and death. The U.S. has seen its worst measles years in more than three decades recently, including thousands of cases in 2026.

When your child needs the MMR

Following the AAP schedule:

• First dose: 12 to 15 months
• Second dose: 4 to 6 years
• Traveling abroad with a baby 6 to 11 months old? Your baby can get an early dose before the trip. They'll still need two more doses on the usual schedule.

Common side effects

Most children have no problems. Some get a sore arm, or a fever or mild rash about one to two weeks after the shot. Serious reactions are very rare.

Let's talk about it

We follow the science, and we also know that trust is built through conversation. If you have questions about the MMR or any vaccine, bring them to your next visit, or call 212-427-0540. We'd much rather talk them through with you than have you worry. See our vaccine and well visit schedule, or read about the AAP and CDC vaccine schedules.

Source: American Academy of Pediatrics, HealthyChildren.org: Vaccine Safety: Examine the Evidence and AAP: Vaccines, safe and effective, no link to autism.