The United States reported more than 2,000 measles cases in 2025, federal data shows, a higher annual total than the country has seen in decades.

Ongoing outbreaks — particularly in the upstate region of South Carolina and along the border between Arizona and Utah — continue to add dozens of cases each week, threatening the measles elimination status that the US has held for a quarter-century.

As of December 30, there have been 2,065 confirmed measles cases in the US in 2025, according to data published Wednesday by the US Centers for Disease Control and Prevention. The last time there were more than 2,000 cases reported in one year was in 1992, just a couple years after health leaders updated recommendations to say that children should get two doses of the measles-mumps-rubella (MMR) vaccine instead of just one.

Measles is one of the most contagious diseases known, but the MMR vaccine offers highly effective protection. One dose is 93% effective against measles infection, and two doses are 97% effective, according to the CDC.