Arizona Attorney General Kris Mayes is spearheading a coalition of states in a legal challenge to sweeping changes made to the nation’s childhood immunization policy, arguing the federal government sidestepped established scientific processes and jeopardized children’s health.
The lawsuit, filed Tuesday, targets Robert F. Kennedy Jr. in his role as Secretary of the U.S. Department of Health and Human Services, along with acting leadership at the Centers for Disease Control and Prevention. At issue is a January 5, 2026 CDC decision memo that removed seven vaccines — including those protecting against hepatitis B, influenza, COVID-19 and RSV — from the agency’s universally recommended childhood immunization schedule.
In court filings, the states contend the changes were enacted without the customary scientific review and without guidance from a lawfully constituted Advisory Committee on Immunization Practices, known as ACIP. The complaint further challenges the restructuring of that advisory panel, alleging that long-standing members were dismissed and replaced with individuals who lack the qualifications required under federal law.
“For decades, the CDC’s immunization schedule has been built on rigorous science and has saved countless lives,” Mayes said in a statement announcing the suit. She argued that altering those recommendations without clear scientific backing risks undermining public confidence and increasing preventable disease.
The legal action points to longstanding research underscoring the public health impact of routine childhood vaccines. According to prior CDC estimates cited in the complaint, immunizations administered to children born over the past three decades have prevented hundreds of millions of illnesses and more than a million deaths nationwide, while generating trillions of dollars in economic savings.
The lawsuit also challenges the elimination of the universal hepatitis B birth dose recommendation — a policy that had been in place for nearly 30 years and is credited with sharply reducing perinatal transmission of the virus.
Beyond the scientific debate, the coalition argues the policy shift could strain state health systems. Lower vaccination rates, they contend, would likely lead to more frequent outbreaks, increased Medicaid costs and additional public spending to counter misinformation and revise state-level guidance previously aligned with CDC standards.
Arizona is co-leading the lawsuit with California Attorney General Rob Bonta. Attorneys general from Colorado, Connecticut, Delaware, Maine, Maryland, Michigan, Minnesota, New Jersey, New Mexico, Oregon, Rhode Island and Wisconsin have joined the filing, along with the governor of Pennsylvania.
The states are asking the court to invalidate both the revised immunization schedule and the recent ACIP appointments, and to restore what they describe as a science-driven federal vaccine policy while the case proceeds.
