Although a federal judge in Boston has temporarily blocked the Trump administration’s changes to the US childhood immunization schedule, the US Supreme Court could have two chances over the next year to weigh in on the decision, legal experts say.

US District Court Judge Brian E. Murphy said the sweeping overhaul of federal vaccine recommendations by Health and Human Services (HHS) Secretary Robert F. Kennedy Jr. likely violated a law that governs how public policy changes are made, as did Kennedy’s firing of all 17 members of an influential immunization advisory panel. The ruling means that, at least for now, the federal government must restore vaccination recommendations in place when Kennedy took office, and that the advisory panel—the Advisory Committee on Immunization Practice (ACIP)—cannot take any legal action.

Murphy’s decision was made in response to a lawsuit filed by the American Academy of Pediatrics (AAP) and other leading medical groups, which claimed that the Trump administration violated the Administrative Procedure Act, a law that forbids public officials from making policy changes that are “arbitrary and capricious.” 

The Trump administration has vowed to appeal the court’s decision.

“We look forward to this judge’s decision being overturned just like his other attempts to keep the Trump administration from governing,” HHS spokesperson Andrew Nixon posted on X.

If a federal appeals court rejects the Trump administration’s appeal, the administration “is likely to try to take it up to the Supreme Court on the emergency docket,” said attorney Richard Hughes IV, JD, MPH, who represented the medical groups.

The Supreme Court would have until June or July, when its term ends, to keep the Trump administration’s vaccine policies on hold or to reinstate them, Hughes said at a webinar for journalists today.The Supreme Court could also decide to consider the merits of the case during its next term, which begins in October, and issue a final verdict on how much power Kennedy has to reshape health policy.

ACIP meeting canceled

The AAPfiled suit against HHS in July 2025 over Kennedy’s unilateral changes to COVID vaccine recommendations for children and pregnant women. The suit was amended in January after HHS took a hatchet to the US pediatric immunization schedule, slashing the number of recommended vaccines from 17 to 11. 

Murphy agreed with the medical groups that Kennedy bypassed the scientific process and didn’t follow proper administrative procedures. Thirteen of Kennedy’s handpicked ACIP appointees “appear distinctly unqualified,” Murphy wrote. In response to the ruling, the Centers for Disease Control and Prevention (CDC) canceled the ACIP meetings scheduled for tomorrow and Thursday.

In series of posts on X, ACIP Vice Chair Robert Malone, MD claimed that Murphy defamed him and described Murphy as a “rogue judge” who should be impeached. He posted that he was disappointed that the ACIP was canceled because, “This week was to be an incredibly important ACIP meeting on vaccine injury, the first of its kind—ever.”

Although Murphy’s ruling doesn’t bar Kennedy from seating additional members on the committee, Hughes said the medical groups are likely to challenge any appointment that doesn’t follow established procedure. “If we see additional appointments to ACIP, you can rest assured that we will act,” Hughes said.

Requesting CDC records

Hughes said he has asked to see public records leading up to Kennedy’s restrictions of vaccine access, including his decision to stop universally recommending COVID vaccines and the announcement that the United States would follow Denmark’s vaccine schedule. The records made public so far present an incomplete picture, Hughes said.

“We’re probably going to file a motion to complete the record if the record is incomplete,” Hughes said. If needed, “we’re probably going to ask for extra record discovery that may go as far as asking for some depositions.”

Elizabeth Jacobs, PhD, an epidemiologist and member of the advocacy group Defend Public Health, said in a statement that while yesterday’s ruling is important, “this battle against Kennedy’s public health malpractice is far from over.” 

“We’re going to keep a close eye on whatever ACIP does next and stand ready to continue to support the plaintiffs any way we can and to call out RFK Jr’s anti-science nonsense,” Jacobs added.