Overview
- U.S. measles cases reached 2,012 in 2025, the highest in decades, with roughly 90–93% of infections in people who were unvaccinated or whose status was unknown, according to CDC data.
- South Carolina’s outbreak rose to 153 cases, largely in the Greenville–Spartanburg area, with 145 unvaccinated, 249 people in quarantine, and seven in isolation, state officials said.
- Utah reported 142 cases statewide, including six new pediatric infections in Utah County, as health leaders urge precautions during holiday gatherings and encourage early MMR for some infants.
- Colorado issued a Dec. 12 Denver International Airport exposure alert for DIA’s B Concourse (gates B45 to B84); the traveler was vaccinated, lowering but not eliminating risk, and potentially exposed people should monitor for symptoms through Jan. 2 and call ahead before seeking care.
- Massachusetts health officials warned of possible exposures linked to an out-of-state visitor at Boston Logan Terminals B and C and a Westborough hotel on Dec. 11–12, advising unvaccinated individuals to review vaccination and watch for symptoms.