2025 has proven to be a nightmare year for measles, with the U.S. reaching a toll not seen in decades.

According to the latest data from the Center for Disease Control and Prevention, there have been more than 2,000 recorded cases of measles this year. Most of these infections are occurring among the unvaccinated and  children. Several outbreaks are still ongoing, and the U.S. is likely to lose its official measles-free status as early as next month.

A record-setting year

As of Dec. 23, there have been 2,012 confirmed measles cases in the U.S., the CDC reported last week.

The tally is the highest seen since measles was locally eliminated in the U.S. in 2000, surpassing the previous modern high of 1,274 cases in 2019; it’s also the most since 1992, which saw over 2,000 cases. However, experts have said that these current numbers are almost certainly an underestimate.

The largest outbreak began in early January along parts of Western Texas. But measles has spread far and wide across the U.S. this year, with cases seen in 43 states, along with 50 separate outbreaks. About two-thirds of reported cases have occurred among children under the age of 18, and 93% involved people who were unvaccinated or had an unknown vaccination status. Three people in the U.S. have died from measles this year, while 227 have been hospitalized.

The official return of measles

Though the Texas outbreak formally ended in August, there is concern that some current outbreaks are genetically linked to it. If that’s true, then we will soon pass the one-year mark of measles circulating locally in the country. And once that happens, the World Health Organization is expected to declare that measles has officially returned to the U.S.

The U.S. would hardly be alone in welcoming measles back. In November, Canada similarly lost its measles elimination status. The viral disease has also resurged in many parts of Europe.

The return of measles has been fueled by waning vaccination rates. It’s a problem that precedes the installment of Robert F. Kennedy Jr.,—a long time enemy of vaccines—as head of the U.S. Department of Health and Human Services. But Kennedy hasn’t helped the situation, either.

Over the past year, for instance, RFK Jr. and his allies have restricted people’s access to certain vaccines. He’s also reduced the workforce of the CDC and other health agencies, as well as personally fired senior officials who refused to back his anti-vaccine policies. And during the Texas measles outbreak, he recommended unsupported treatments like cod liver oil that may have some children. Next year, he may even succeed at the childhood vaccination schedule.