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.”

CDC data contradicts RFK Jr.’s claims, showing that the rise in autism diagnoses is due to improved screening and early detection—not harmful environmental exposures. In 2022, 1 in 31 U.S. 8-year-olds were diagnosed with autism,