If Vaccines Don’t Cause Autism, What Does?

The idea that vaccines cause autism was debunked by scientists some time ago. Yet it won’t go away.

Health and Human Services Secretary Robert F. Kennedy Jr.’s agency, for example, is reportedly launching a new study to look at potential links between vaccines and autism. And vaccine hesitancy is again rearing its head, even as measles outbreaks proliferate across the country.

The skepticism is confounding given that scientists say numerous studies have already shown that the measles-mumps-rubella (MMR) vaccine unequivocally doesn’t cause autism. “We will learn absolutely nothing with another study,” says Helen Tager-Flusberg, director of the Center for Autism Research Excellence at Boston University. “We’ve ruled it out.”

So why do doubts linger? Partly it is because of a since-retracted 1998 study, which was based on fraudulent data from just 12 children, that gave rise to the vaccine-autism theory and continues to fuel conspiracy theories.