The CDC’s latest measles data, updated March 21, shows a rise in confirmed cases across multiple states.
Here are five things to know:
- A total of 378 confirmed measles cases have been reported in 2025, according to the data. Cases have been identified in 18 jurisdictions: Alaska, California, Florida, Georgia, Kansas, Kentucky, Maryland, Michigan, New Jersey, New Mexico, New York City, New York state, Ohio, Pennsylvania, Rhode Island, Texas, Vermont and Washington.
- Seventeen percent of cases, or 64 people, have required hospitalization. Young children are among those most affected, with 27% of children younger than 5 who have contracted measles being hospitalized.
- Three outbreaks have been confirmed this year, and 90% of cases (341) have been linked to outbreaks, a significant increase from 2024, when 69% of cases (198 of 285) were outbreak related.
- Ninety-five percent of reported cases involve individuals who are unvaccinated or have an unknown vaccination status. Two percent of cases involve people who had received two doses of the MMR vaccine.
- The measles outbreak in Texas, New Mexico and Oklahoma may last for up to a year, a Texas health official said in a press briefing March 18. Texas measles cases have reached 309, the state Department of Health reported March 21, up from 279 the previous week. New Mexico reported 42 cases as of March 21, up from 38, and Oklahoma has reported four probable cases. In response, the Oklahoma State Department of Health said it will begin releasing weekly notices of measles cases.