FILE PHOTO: U.S. Secretary of Health and Human Services Robert F. Kennedy Jr. speaks with U.S. Vice President JD Vance (not pictured) during the inaugural Make America Healthy Again (MAHA) summit in Washington, D.C., U.S., November 12, 2025. REUTERS/Nathan Howard/File Photo
A sign supporting workers at the Centers for Disease Control and Prevention is displayed outside of the entrance to the CDC main campus in Atlanta, Georgia, U.S., November 20, 2025. REUTERS/Alyssa Pointer

(Reuters) -Health Secretary Robert F. Kennedy Jr. said in an interview with the New York Times that he personally instructed the U.S. Centers for Disease Control and Prevention to change its longstanding position that vaccines do not cause autism.

Countering decades of science showing vaccines to be safe, the U.S. public health agency's website was changed to say, "The claim 'vaccines do not cause autism' is not an evidence-based claim because studies have not ruled out the possibility that infant vaccines cause autism."

In the interview, Kennedy said that while the large-scale epidemiological studies of the measles, mumps and rubella vaccine had found no link to autism, and that studies of the mercury-based preservative thimerosal had also shown no link, there are gaps in the vaccine safety science.

"The whole thing about 'vaccines have been tested and there's been this determination made,' is just a lie," Kennedy said in his first interview with a major print publication.

Kennedy is a longtime vaccine skeptic and not a scientist. Before he took up his role as head of Health and Human Services, the CDC was a key opponent of growing global anti-vaccine sentiment.

"The phrase 'Vaccines do not cause autism' is not supported by science," Kennedy said.

Public health experts, doctors and scientists have decried the update as the kind of misinformation the CDC has fought for decades as it promoted the use of life-saving childhood vaccines both in the U.S. and abroad.

The World Health Organization and other health agencies around the world have repeatedly said evidence shows vaccines do not cause autism.

"Many large-scale studies in hundreds of thousands of children across the world have thoroughly investigated the claim that vaccines cause autism and found no link between vaccines and autism. Based on existing evidence, vaccines do not cause autism," the European Centre for Disease Prevention and Control said on Thursday.

In the interview, Kennedy said he ordered the CDC to change its guidance in part because high-quality large studies had not been conducted to examine a potential link between autism and other shots given in the first year of life.

Those include the hepatitis B vaccine and a combination shot that protects against diphtheria, tetanus and pertussis, commonly known as whooping cough.

A revamped committee that advises the CDC on vaccine policy is scheduled to meet early next month to consider new recommendations for hepatitis B vaccines.

(Reporting by Sriparna Roy in Bengaluru and Michael Erman in New Jersey; Editing by Alan Barona)