The Pan American Health Organization (PAHO) has revoked the United States' measles elimination status after determining the country failed to halt continuous transmission of the highly contagious virus for more than a year, according to researchers with direct knowledge of the decision.
The decision was confirmed on Nov. 13 and was set to be publicly announced on Nov. 17, per reporting from KFF Health News and The Wall Street Journal. PAHO, the Americas branch of the World Health Organization (WHO), based its assessment on two analyses: one by the U.S. Centers for Disease Control and Prevention (CDC) and another by an independent regional verification commission.
Measles elimination status is lost when a country no longer meets the WHO standard of no locally transmitted infections or outbreaks lasting 12 months or longer. The U.S. had held this status since 2000.
Immediate Impact and Scope
Since 2025, the U.S. has recorded over 7,500 measles cases and 13 deaths, including infants in New York, Pennsylvania, and Wisconsin. The CDC reported 5,412 confirmed cases in 2026 through Nov. 12, more than double the 2,289 cases reported in all of 2025. Hospitalizations have exceeded 830, with an estimated $125 million in medical and productivity costs.
Measles cases have been confirmed in 45 states and Washington, D.C., with Pennsylvania reporting the largest outbreak at over 1,500 cases and seven deaths. New York and Wisconsin each reported one death.
What Measles Elimination Status Means
A country achieves measles elimination status when it demonstrates no continuous, locally transmitted outbreaks for 12 months or longer. This status does not imply zero cases but rather that imported cases do not lead to sustained spread. The threshold for maintaining elimination is 95% vaccination coverage, which creates herd immunity to protect unvaccinated individuals.
Vaccination and Public Health Response
Public health experts emphasize that two doses of the measles-mumps-rubella (MMR) vaccine prevent about 97% of infections. The current outbreaks have occurred in communities with lower vaccination rates, allowing the virus to spread. Infants under one year old, who are not yet eligible for vaccination, are particularly vulnerable.
The CDC and state health departments continue to monitor cases and coordinate responses, including contact tracing and vaccination campaigns. The loss of elimination status does not affect the efficacy of the vaccine but highlights gaps in population immunity.
Historical Context
The U.S. achieved measles elimination in 2000 through widespread immunization programs and public health initiatives. The current resurgence follows a decades-long decline in vaccination rates and rising vaccine hesitancy, a trend noted in multiple reports.