The U.S. could lose its measles elimination status after more than 5,100 confirmed cases in 2026. Transmission has persisted for more than 12 months in multiple parts of the country, threatening a status it has held since 2000.
The 2026 case count is already more than double the 2025 total. Dozens of outbreaks and several deaths have been recorded as vaccination rates have declined in some communities.
Elimination means ongoing domestic transmission has been interrupted. Imported cases can still occur without a country losing that designation. Sustained spread within the U.S. is what’s putting its status at risk.
Independent experts convened by the Pan American Health Organization are meeting November 10 to 13 in Washington to review the U.S. data and assess other countries, including Mexico and Bolivia.
Public health experts say the evidence points strongly to measles becoming established again, and a decision on the U.S. designation could come as soon as early next week. Canada lost its elimination status in 2025.
A change in designation would formally acknowledge the continuing spread. The immediate priorities remain containing outbreaks and raising coverage with the measles, mumps and rubella vaccine, known as MMR. Countries can regain elimination status after stopping transmission for the required period.
