The Pan American Health Organization (PAHO) has issued a new epidemiological alert for measles in the Region of the Americas, urging countries to strengthen surveillance, vaccination, and rapid outbreak response measures to interrupt transmission and protect vulnerable populations. The alert comes amid ongoing cases and outbreaks in several countries, reflecting a sustained rise in measles incidence in 2025 compared with the previous five years, a trend that appears to be continuing into 2026.
In 2025, a total of 14,891 confirmed measles cases and 29 deaths were reported across 13 countries in the Region, including significant outbreaks in Canada, the United States, and Mexico. This marked a dramatic increase from the 466 cases reported in 2024. Early data from 2026 show 1,031 additional confirmed cases in seven countries during the first three weeks of the year, representing a 43-fold increase compared with the same period in 2025. The majority of confirmed cases with vaccination information were unvaccinated, while infants under one year of age experienced the highest incidence rates, followed by children aged 1–4 and 5–9 years, highlighting the critical need for complete vaccination schedules and protective measures in outbreak settings.
Globally, the World Health Organization reported over 552,000 suspected measles cases in 2025 across 179 countries, with nearly 45% confirmed, illustrating a worldwide resurgence of the disease driven by persistent gaps in immunization coverage. In the Americas, regional vaccination coverage for the measles, mumps, and rubella (MMR) vaccine showed modest increases in 2024 but remained below the 95% threshold needed to prevent outbreaks, with only a minority of countries reaching this target. Approximately 1.5 million children in the Region did not receive any dose of the vaccine in 2024.
PAHO emphasized that measles is highly contagious but preventable through timely administration of two MMR vaccine doses. Countries experiencing active outbreaks are urged to intensify vaccination campaigns, conduct active case finding, and ensure rapid responses to interrupt transmission. Across the Region, closing vaccination gaps, maintaining sensitive surveillance systems, and protecting travelers through immunization remain critical. In light of mass gatherings such as the 2026 FIFA World Cup, PAHO recommends enhancing surveillance sensitivity to promptly detect measles and rubella cases and prevent further spread.
