The number of confirmed measles cases in the United States has surpassed the total recorded for all of 2025, the Centers for Disease Control and Prevention said, as the agency urged families to verify vaccinations before the school year. The CDC pointed to clusters in undervaccinated communities across several states.

Measles was declared eliminated in the United States in 2000, but repeated outbreaks in recent years have eroded that status. The CDC has attributed the resurgence to declining childhood immunization coverage and imported cases linked to international travel. Two doses of the measles, mumps and rubella vaccine are about 97 percent effective, according to the agency.

State health departments in Texas, New Mexico and other affected areas have reported ongoing transmission tied to schools, religious gatherings and households with low vaccination rates. Most confirmed patients were unvaccinated or had unknown vaccination status, and several required hospitalization.

Pediatric groups, including the American Academy of Pediatrics, have called on parents to catch up on missed shots before classes resume in August. Public health officials warned that gaps in coverage could allow further spread as students return to crowded classrooms and travel resumes.

The CDC said it was working with state and local partners to expand vaccination clinics and contact tracing in affected areas. The agency urged clinicians to consider measles in patients presenting with fever and rash.