U.S. Health and Human Services Secretary Robert F. Kennedy Jr. is aggressively advancing sweeping changes to the nation’s vaccine policies, despite significant opposition from scientists, lawmakers, and public health experts. Since taking office, Kennedy has restricted eligibility for COVID-19 vaccines, removed the country’s top public health official, expanded federal support for state-level vaccine exemptions, dismantled the vaccine recommendation review process, and reshaped a national vaccine advisory board with like-minded experts. These actions have drawn sharp criticism from medical societies, Democrats in Congress, and even members of Kennedy’s own family, who have called for his removal. Public health leaders warn that his policies could restrict access to critical vaccines for children, potentially reversing decades of progress in immunization. Kennedy’s supporters, however, argue that his efforts aim to restore public trust in health agencies and promote greater scrutiny of vaccine safety. The ongoing debate comes as a Kennedy-appointed advisory board prepares to vote on potential changes to childhood vaccine recommendations, a decision that could have far-reaching implications for public health nationwide.