Washington DC, November 10, 2025 (PAHO) – The Pan American Health Organization (PAHO) announced today that the Americas have lost their status as a region free of endemic measles transmission.

The decision was made after the meeting of the PAHO Regional Commission for Monitoring and Reverification of the Elimination of Measles, Rubella and Congenital Rubella Syndrome (CVR), held in Mexico City from November 4 to 7, 2025, in order to evaluate the epidemiological situation in the region.

The Commission determined that endemic measles transmission has re-established 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 again lost its measles-free status. All other countries in the region continue to maintain their status.

“This loss represents a setback, but it is also reversible,” said Dr. Jarbas Barbosa, Director of PAHO, during a press conference. “As long as measles is not eliminated globally, our region will continue to face the risk of reintroduction and spread of the virus among unvaccinated or incompletely vaccinated populations. However, as we have previously demonstrated, with political commitment, regional cooperation and sustained vaccination, the region can once again interrupt transmission and regain this collective achievement,” he added.

Current situation

As of November 7, 2025, 12,596 confirmed cases of measles have been reported in ten countries (approximately 95% of the region’s cases are concentrated in Canada, Mexico and the United States), which represents a 30-fold increase compared to 2024. In addition, 28 deaths have been recorded: 23 in Mexico, three in the United States and two in Canada.

Active outbreaks persist in Canada, Mexico, the United States, Bolivia, Brazil, Paraguay and Belize, most associated with imported cases. Transmission has mainly affected communities with low vaccination coverage; 89% of cases correspond to unvaccinated people or people with unknown vaccination status. Children under 1 year of age are the most affected group, followed by those between 1 and 4 years of age.

The measles outbreak in Canada began in October 2024 in the province of New Brunswick and has since spread across the country, with more than 5,000 confirmed cases. Although they are declining, transmission continues in Alberta, British Columbia, Manitoba and Saskatchewan.

Measles is highly contagious and a single infected person can transmit it to up to 18 other people. It can cause serious complications such as pneumonia, encephalitis, blindness and death. Outbreaks also disrupt daily life and place additional pressure on health systems.

Vaccination remains the most effective protection measure. In the last 25 years, the measles vaccine has prevented more than six million deaths in the Americas, and it is estimated that it has prevented around 15 million deaths in the last 50 years. However, in 2024, regional coverage of the second dose of the measles, rubella and mumps (MMR2) vaccine was, on average, 79%, well below the 95% needed to prevent outbreaks. Only 31% of countries achieved coverage of 95% or more for the first dose, and only 20% achieved that level for the second dose.

PAHO response and recommendations

PAHO continues to provide technical cooperation to countries to strengthen surveillance, laboratory diagnosis, outbreak response, and vaccination campaigns. Experts have been sent to Mexico, Argentina and Bolivia, and the Organization monitors risks in Belize, Brazil and Paraguay.

Dr. Barbosa emphasized: “Every case we prevent, every outbreak we manage to stop saves lives, protects families and strengthens communities. Today, more than lamenting the loss of a regional status, we call on all countries to redouble efforts, strengthen vaccination, surveillance and timely response to suspected cases, reaching all corners of the Americas. As a Region, we have eliminated measles twice. We can do it a third time.”

The RVC recommends that countries:

• Continue strengthening surveillance, immunization and rapid outbreak response activities for each suspected case.
• Expand and consolidate electronic vaccination records in all countries, in accordance with PAHO guidelines.
• Maintain sustainable laboratory surveillance by allocating sufficient financial and human resources.
• For suspected cases with clinical and epidemiological risk factors and a negative IgM result for measles (with samples taken within 0 to 3 days after the onset of the rash), perform PCR tests to confirm or rule out infection.
• Implement all recommendations at the local level.
• Document the closure of outbreaks in accordance with the Regional Framework guidelines.

Looking forward

The Americas have faced previous setbacks, including the temporary loss of measles elimination status in Venezuela (2018) and Brazil (2019). The region regained this status in 2024 thanks to coordinated regional action.

To regain 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 the PAHO regional framework, focused on increasing vaccination coverage, strengthening surveillance systems and ensuring rapid responses to outbreaks, with the goal of stopping endemic transmission and regaining measles elimination.

“Cooperation, solidarity and science are stronger than any virus. When we work together, we protect the health and lives of all people in the Americas,” concluded Dr. Barbosa.