The reestablishment of measles transmission in recent years poses challenges to maintaining the Region’s elimination goals. These developments underscore the urgent need to restore and sustain high immunization coverage through routine immunization and follow-up vaccination campaigns, strengthen outbreak preparedness, and maintain sensitive surveillance systems. In this regard, restoring and sustaining immunization coverage following pandemic‑related disruptions was a major outcome of the 2024–2025 biennium. 

During the period 2020–2025, measles incidence declined sharply following the 2019 epidemic peak of 22.9 cases per million population, falling to 8.5 cases per million in 2020 and reaching an all-time low in 2023, when only 73 cases were reported. In the immediate post‑pandemic period, relatively few confirmed measles cases were reported (fewer than 150), likely reflecting reduced population mobility and border closures that significantly affected international travel. Measles reemerged in 2024 and 2025, however, indicating renewed vulnerability to outbreaks and challenges in mounting rapid outbreak responses. 

This trend reflects the gradual recovery of routine first- and second-dose measles vaccination coverage following the COVID-19 pandemic, compounded by persistently suboptimal coverage with two-doses of measles- and rubella (MR/MMR)-containing vaccines (below 95%), accumulated immunity gaps, and vaccine hesitancy in close-knit communities. In addition, surveillance gaps, delayed outbreak detection, and misalignment between vaccine supply and epidemiological risk have hindered response efforts. As a result, the Region of the Americas can no longer be considered measles‑free. This indicator is considered to be on the wrong track. 

Timely detection, notification, investigation and rapid response for every suspected case remain critical to sustaining elimination achievements. Sustained laboratory capacity is also essential for timely case confirmation and viral genotyping.