Washington, D.C., 2 March 2026 (PAHO) — The Pan American Health Organization (PAHO) informs that the review of the measles elimination status in the United States and Mexico will take place in November 2026, during the Commission’s regular annual meeting of the Regional Verification Commission for the Elimination of Measles, Rubella, and Congenital Rubella Syndrome (RVC). This review will include all Member States, with particular focus on those with active outbreaks and those that have completed one year of sustained transmission, in accordance with established criteria.
The decision to conduct these reviews during the regular annual meeting aims to simplify and harmonize the process within the Commission’s regular schedule. In the case of the U.S., it also takes into account the ongoing analysis being conducted by its health authorities, which includes complete viral genome sequencing, including the development of a bioinformatics platform for detailed molecular data analysis, alongside ongoing efforts to support outbreak control.
For both the United States and Mexico, the analysis period for assessing the possible re-establishment of endemic measles transmission corresponds to one year from the onset of the reported outbreaks: 20 January 2025 in the United States and 1 February 2025 in Mexico.
Within its mandate, the Commission reviews the situation of all countries in the Americas annually. Each Member State submits an annual report, which is examined by the RVC. Countries that have experienced outbreaks provide additional information on the course of the event, measures taken to control it, and criteria used to declare the outbreak closed, as applicable.
The RVC is an independent technical body reporting directly to the Director of PAHO. Its role is to monitor and verify the elimination of measles, rubella, and congenital rubella syndrome in the region, as well as to assess any possible re-establishment of endemic transmission, defined as uninterrupted circulation of the same virus genotype and lineage for 12 months or more in a specific geographic area.
Following its review, the Commission presents its recommendations to the Director of PAHO, who formally communicates the corresponding classification to national authorities.
PAHO reiterates the importance of maintaining high and homogeneous vaccination coverage, strengthening epidemiological surveillance, and ensuring timely outbreak response, as essential pillars to halt transmission and sustain measles elimination in the countries of the Americas.
In November 2025, the region lost its status as free of endemic measles transmission following the RVC’s assessment, which concluded that endemic transmission had been re-established in Canada, where the virus circulated uninterrupted for at least 12 months. In accordance with the regional framework, the loss of regional status occurs when endemic transmission is documented in any country within the region.
