The Pan American Health Organization pushed the evaluation of the United States’ measles elimination status from April to November 2026.
RT’s Three Key Takeaways:
- Elimination Status Review: The Pan American Health Organization (PAHO) will review the measles elimination status of the US and Mexico in November 2026.
- Endemic Transmission Criteria: Endemic transmission is defined as the uninterrupted circulation of the same virus genotype for 12 months or more in a specific area.
- Regional Impact: The Americas lost the status as a region free of endemic measles in November 2025 after transmission was re-established in Canada.
The Pan American Health Organization (PAHO) will review the measles elimination status of the US and Mexico in November 2026, according to the organization. The review will take place during the annual meeting of the Regional Verification Commission for the Elimination of Measles, Rubella, and Congenital Rubella Syndrome (RVC).
This assessment will include all member states, with a specific focus on those experiencing active outbreaks or those that have completed one year of sustained transmission. For the US and Mexico, the analysis period for assessing the possible re-establishment of endemic transmission corresponds to one year from the onset of reported outbreaks: 20 January 2025 in the US and 1 February 2025 in Mexico.
The RVC, an independent technical body reporting to the director of PAHO, defines endemic transmission as the uninterrupted circulation of the same virus genotype and lineage for 12 months or more in a specific geographic area.
In the US, health authorities are conducting viral genome sequencing and developing a bioinformatics platform for molecular data analysis to support outbreak control efforts. These technical analyses will be considered by the commission during the November meeting.
In November 2025, the Americas region lost its status as free of endemic measles transmission after the RVC concluded that endemic transmission had been re-established in Canada. Under the regional framework, the loss of regional status occurs if endemic transmission is documented in any single country within the region.
Each member state submits an annual report to the RVC, and countries with outbreaks provide additional data on control measures and the criteria used to declare outbreaks closed. Following the review, the commission will present recommendations to the director of PAHO, who then communicates the classification to national authorities.
PAHO reiterated that maintaining high vaccination coverage, strengthening epidemiological surveillance, and ensuring timely outbreak response are essential to halting transmission and sustaining measles elimination in the Americas.
