South Carolina has been by far the hardest-hit state this year, with 632 CDC-confirmed cases, followed by Utah (117), Florida (64), and Arizona (36).
Of the 300 measles cases, 58 have been identified in the past 3 weeks.
The South Carolina Department of Public Health announces 12 more measles cases in an ongoing outbreak.
Vermont and New York health officials are reporting their first measles cases of the year, bringing the country's total numbers of measles infections in 2026 to 910.
The perceived safety of the MMR vaccine is now 83% (down from 86%).
More than two-thirds of all cases (594) in South Carolina have occurred in children ages 5 to 17.
Preliminary data from 2025 show a drop in the number of measles cases reported across the European Union compared with 2024.
Among US measles patients, 95% are unvaccinated or have an unknown vaccine status, compared with 4% who are fully vaccinated.
Florida has the fourth most measles cases so far in 2026, with 21 confirmed.
DHS says all movement within the facility has stopped.
