A federal judge on Monday blocked Health and Human Services Secretary Robert F. Kennedy Jr.'s recent changes to federal vaccine policy, including reductions to recommended childhood immunizations and restructuring of a key vaccine advisory panel.

U.S. District Judge Brian E. Murphy, appointed during the Biden administration, granted a motion filed by the American Academy of Pediatrics challenging the policy modifications. The ruling temporarily halts implementation of the changes while legal proceedings continue.

Kennedy's policy adjustments had reduced the number of recommended childhood vaccinations and involved significant changes to the composition and structure of the federal vaccine advisory committee that provides guidance on immunization schedules.

The American Academy of Pediatrics argued that the changes could potentially impact public health protections and established vaccination protocols that have been developed over decades of medical research and practice.

The case represents an early legal challenge to Kennedy's approach to vaccine policy since taking office as HHS Secretary. The ruling means current federal vaccine recommendations and advisory panel structure remain in place pending further court proceedings.