This is The New Yorker Radio Hour, a co-production of WNYC Studios and The New Yorker.

Welcome to The New Yorker Radio Hour. I'm David Remnick.

When you hear 10,000, it was 1 in 10,000 and now it's 1 in 31 for autism, I think that's just a terrible thing.

It has to be something on the outside, has to be artificially induced, has to be.

Donald Trump's operating procedure involves dismissing expertise of all kinds, economic,

diplomatic, scientific, you name it.

But when he made an alliance with Robert F. Kennedy,

Jr., he brought one particular conspiracy theory into the center of the MAGA agenda,

the idea that vaccines are responsible for the rise in autism rates. Kennedy, who's now the

Secretary of Health and Human Services Services has long advanced that notion.

Of course, it's been thoroughly discredited by scientists,

but the discrediting has only fueled some people's belief that it must be true.

According to one survey, as many as one in four Americans today believe

that vaccines are linked to autism.

Kennedy is not a doctor. He's not a autism. Kennedy is not a doctor.

He's not a scientist.

But as the nation's senior figure in public health,

he shocked the medical community and families across the country recently

when he said that his agency would soon reveal the cause of autism once and for all.

We've launched a massive testing and research effort that's going to involve

hundreds of scientists from around the world. By September, we will know what has caused

the autism epidemic and will be able to eliminate those exposures.

...