The United States has now recorded more cases of measles in 2026 than in any other year since the virus was declared eliminated in 2000, a grim sign that the country may be headed toward a new era in which the disease regularly sickens thousands every year.

On Friday, the Centers for Disease Control and Prevention announced that there have been 2,318 confirmed cases of measles so far this year. The case count toppled the record set last year, when measles infected more than 2,200 Americans and killed two unvaccinated children. More measles cases have been reported in the United States in the last two years than in all the years from 2000 through 2024 combined.

Reversing course on measles would require a nationwide push to improve vaccination rates, a prospect that experts said seemed unlikely under the leadership of Health Secretary Robert F. Kennedy Jr. He has halted funding for vaccine hesitancy research, downplayed the risks of measles and spearheaded a hunt for evidence that vaccines are unsafe.

In November, a panel of international experts will meet to determine whether the United States has lost its elimination status, which has long been viewed as one of the country’s crowning public health achievements.

“This is just going to keep happening,” said Jennifer Nuzzo, director of the Pandemic Center at the Brown University School of Public Health. “It’s going to mean living in a perpetual state of vulnerability and risk until we get vaccination levels up.”

Many of the cases reported this year were tied to a large outbreak in South Carolina that took root last October in a close-knit, evangelical Slavic community and quickly became the largest outbreak in the United States since 2000. The outbreak, which ultimately sickened nearly 1,000 people, was declared over by state health officials in April.