During the executive order signing, Kennedy and Trump suggested that childhood vaccines may play a role in causing autism. But studies by the CDC and others have ruled that out. A fraudulent single study that claimed a link between the measles, mumps and rubella vaccine was later retracted by the journal that published it.

Trump's vaccine order would end universal recommendations for a number of childhood shots, while keeping 11 on the schedule.

U.S. President Donald Trump will sign an executive order on Monday "calling for more vaccine flexibility and research."

MMR vaccine would be broken into separate shots under order, putting a financial and logistical strain on families