Overview
- The CDC tallied 2,065 measles cases in 2025, the most in the United States since 1991 and more than seven times the 2024 total.
- South Carolina reported 185 cases concentrated in the upstate region, with state officials saying 172 patients were unvaccinated and most are under 17.
- An outbreak along the Arizona–Utah line exceeded 350 cases in 2025, and health authorities warn that continued spread could jeopardize the nation’s elimination designation later in January.
- MMR coverage among incoming kindergarteners fell to 92.5% for 2024–25, below the ~95% level needed to prevent outbreaks, even though one dose is 93% effective and two doses are 97% effective.
- South Carolina has nearly 300 people in quarantine as transmission continues in households, schools and churches, while a West Texas outbreak earlier in 2025 was declared over after hundreds of cases and three unvaccinated deaths.