US to lose crucial public health status — decades after eliminating ‘world’s most contagious disease’

US health officials may lose measles elimination status, a milestone achieved in 2000 after vaccination ended continuous spread within the country. A Pan American Health Organization commission is due to review whether measles has circulated continuously for at least 12 months, which would mean it is endemic again.

Genetic data identified three transmission chains still active in July 2026, linked to a Texas outbreak more than a year earlier; one continued in Utah through September. The US reported 5,182 confirmed cases in 2026, the highest annual total in 35 years, with 562 hospitalisations and eight deaths. MMR coverage among kindergartners was 92.4% in the 2025–26 school year, below the 95% level generally needed for community protection.