The Centers for Disease Control and Prevention revised a vaccine-safety webpage to state that a causal link between vaccines and autism cannot be entirely ruled out — a marked change from the agency’s longstanding assertion that vaccines do not cause autism. The wording change and a stated HHS review of possible biologic mechanisms prompted immediate pushback from pediatric and public-health experts. HHS Secretary Robert F. Kennedy Jr. has promoted vaccine-safety skepticism, and Department spokesperson Andrew Nixon acknowledged updates and an ongoing assessment. Leading medical groups including the American Academy of Pediatrics and independent epidemiologists criticized the change, warning it risks undermining vaccine confidence and could depress routine immunizations. Scientific outlets reported experts calling the move “anti-science” and warned of public-health consequences if uptake falls.