March 17, 2026
A federal judge in Massachusetts on Monday granted a temporary injunction blocking parts of Health and Human Services Secretary Robert F. Kennedy Jr.’s recent changes to federal vaccine policy. The pause affects several directives that medical groups said would weaken established childhood vaccination practices if allowed to take effect.
Multiple medical organizations brought the lawsuit, arguing the shifts—from revised federal guidance on childhood immunizations to modifications touching school-entry rules and vaccine reporting—exceeded the secretary’s statutory authority. The plaintiffs told the court the changes threatened public health by likely reducing vaccination coverage and creating confusion and additional burdens for health care providers. They sought emergency relief, saying immediate implementation would cause irreparable harm to pediatric vaccination programs and children’s health outcomes.
In granting the temporary halt, the judge found the plaintiffs had shown a likelihood of success on important legal claims and would face irreparable harm without an injunction. The order stops enforcement of the specified provisions while the case proceeds through litigation; it does not resolve the underlying legal questions on the merits.
HHS, led by Secretary Kennedy, defended the policy changes as lawful uses of regulatory authority aimed at increasing transparency and parental involvement in vaccination decisions. The department said it will review the ruling and is considering an appeal.
For now, existing vaccine policies remain in place. The decision sets the framework for additional briefing and a fuller hearing on the legality and public-health implications of the secretary’s actions, and either side may seek expedited consideration as the federal case moves forward.