A federal judge on Monday blocked Health Secretary Robert F. Kennedy Jr. from carrying out vaccine policy changes recommended by his handpicked advisory committee, including a dramatic overhaul of the childhood vaccination schedule.Why it matters: The injunction from U.S. District Court Judge Brian Murphy is another blow to Kennedy's efforts to overhaul federal vaccine policy at a time when the White House is seeking to limit vaccine critics' influence within the administration.It doesn't prevent the panel from holding a scheduled meeting this week, but stays the advisers' appointments and any votes on further policy changes.Driving the news: Murphy, a Biden appointee, wrote that the vaccine policy changes should be paused because the Department of Health and Human Services likely violated administrative procedure. It's also likely that Kennedy's advisory committee doesn't comply with federal law, he wrote. The decision came in response to a request from the American Academy of Pediatrics and other medical associations asking the U.S. District Court of Massachusetts to halt new vaccine recommendations — including the administration's cuts to the number of recommended childhood shots.The request is part of a broader lawsuit the medical groups have brought against Kennedy, which asks the court to void all of the votes taken by the Advisory Committee on Immunization Practices over the past year.The pause is temporary as the lawsuit continues to move through court. HHS did not immediately respond to a request for comment. What it says: "[T]he Government removed all duly appointed members of ACIP and summarily replaced them without undertaking any of the rigorous screening that had been the hallmark of ACIP member selection for decades," Murphy wrote. This "highlights the very reasons why procedures exist and raises a substantial likelihood that the newly appointed ACIP fails to comport with governing law." Flashback: The vaccine advisory panel, which advises the Centers for Disease Control and Prevention, has voted to endorse several changes to vaccine standards over the past year, including dropping the recommendation that all infants receive a Hepatitis B shot.