The Pan American Health Organization (PAHO) announced today that the Region of the Americas has lost its verification as free from endemic measles transmission.
The decision follows the conclusion of the PAHO Measles, Rubella, and Congenital Rubella Syndrome Elimination Regional Monitoring and Re-Verification Commission, which met in Mexico City from 4 to 7 November 2025 to review the epidemiological situation across the region.
The Commission determined that endemic measles transmission has been reestablished in Canada, where the virus has circulated for at least 12 months.
As a result, the Americas, which was the first region in the world to eliminate measles twice, has now lost its measles-free status. All other countries continue to maintain their measles elimination status.
“This loss represents a setback—but it is also reversible,” said Dr. Jarbas Barbosa, Director of PAHO. “Until measles is eliminated worldwide, our Region will continue to face the risk of reintroduction and spread of the virus among unvaccinated or under-vaccinated populations.
However, as we have demonstrated before, with political commitment, regional cooperation, and sustained vaccination, the Region can once again interrupt transmission and reclaim this collective achievement.”
Current situation
As of 7 November 2025, 12,593 confirmed measles cases have been reported across ten countries (approximately 95% of the Region’s cases in Canada, Mexico and US), a 30-fold increase compared to 2024. Twenty-eight deaths have been recorded: 23 in Mexico, 3 in the United States, and 2 in Canada.
Active outbreaks are ongoing in Canada, Mexico, the United States, Bolivia, Brazil, Paraguay, and Belize, mostly triggered by imported cases. Transmission has primarily affected under-vaccinated communities, with 89% of cases occurring in unvaccinated individuals or those with unknown vaccination status. Children under 1 year of age are the most affected, followed by those aged one to four years.
Canada’s measles outbreak began in October 2024 in the province of New Brunswick and has since spread nationwide, with more than 5,000 confirmed cases reported nationwide. Although declining, transmission persists in Alberta, British Columbia, Manitoba, and Saskatchewan.
Measles is highly contagious. A single infected person can transmit it to up to 18 others. Severe complications can include pneumonia, encephalitis, blindness, and death. Outbreaks also disrupt daily life and place additional pressure on health systems.
Vaccination remains the most effective means of protection. Over the past 25 years, the measles vaccine has prevented more than six million deaths across the Americas —and an estimated 15 million deaths over the last 50 years. Nevertheless, in 2024, regional coverage for the second dose of the measles, mumps and rubella vaccine (MMR2) averaged 79%—well below the 95% needed to prevent outbreaks. In addition, only 31% of countries reached 95% or more coverage for the first dose, and just 20% achieved that level for the second dose.
PAHO’s response and recommendations
PAHO continues to provide technical support to countries to strengthen surveillance, laboratory diagnosis, outbreak response, and vaccination campaigns. Experts have been deployed to Mexico, Argentina, and Bolivia, and the organization is monitoring risks in Belize, Brazil and Paraguay.
Dr. Barbosa emphasized: “Every case we prevent, every outbreak we stop saves lives, protects families, and makes communities healthier. Today, rather than lamenting the loss of a regional status, we call on all countries to redouble their efforts to strengthen vaccination rates, surveillance, and timely response to suspected cases—reaching every corner of the Americas. As a Region, we have eliminated measles twice. We can do it a third time.”
RVC strongly encourages countries to:Continue strengthening surveillance, immunization and outbreak rapid response activities for every suspect case.Expand and consolidate electronic immunization registries across all countries, following PAHO’s established guidelines.Maintain sustainable laboratory surveillance by allocating sufficient financial and human resources.For suspected cases with clinical and epidemiological risk factors and a negative measles IgM result (with specimens collected within 0–3 days after rash onset), perform PCR testing to confirm or rule out infection.Implement all recommendations down to the local level.Document outbreak closure following the Regional Framework guidelines.Looking forward
The Americas have previously faced setbacks, including temporary loss of measles elimination status in Venezuela (2018) and Brazil (2019). The region regained elimination status in 2024 through coordinated regional action.
To regain measles elimination status, a country must demonstrate interruption of endemic transmission for at least 12 consecutive months, supported by comprehensive vaccination, surveillance, and outbreak-response data.
Canada will now present and implement an action plan under PAHO’s regional framework, focused on boosting immunization coverage, reinforcing surveillance systems, and ensuring rapid outbreak response to stop endemic transmission and regaining measles elimination status.
“Cooperation, solidarity, and science are stronger than any virus—because when we work together, we protect the health and lives of all people in the Americas,” Dr. Barbosa concluded.
