Health secretary Robert F. Kennedy Jr. says a "massive testing and research effort" will focus on the cause of autism, but his approach has raised alarms.

Kennedy, Hotez says, made a “false statement” in claiming that the scientific community denies that there are any environmental factors at play. “I’ve said to RFK Jr. that there could be an environmental component, but not vaccines, because autism occurs in fetal brain development well before kids ever see vaccines.”