Measles Multi-Country Outbreak: Response Strategy and Donor Appeal

Measles is re-emerging as a serious public health threat across the Americas, driven by growing immunity gaps and conditions that allow the virus to spread rapidly. In 2023, routine vaccination coverage remained well below the 95% level needed to prevent outbreaks, with only 87% of children receiving the first dose of measles-containing vaccine and just 76% receiving the second. These gaps leave millions of people unprotected, especially in close-knit, highly mobile communities and among groups with low vaccine confidence, creating ideal conditions for sustained transmission. 

This resurgence is already leading to increased measles-related deaths, with more fatalities reported in the first half of 2026 than in all of 2025, as larger outbreaks expose more vulnerable, unvaccinated individuals to severe disease. In some countries, such as Guatemala, this represents a stark reversal—shifting from no reported measles deaths in 2025 to multiple deaths during the current outbreak—highlighting how quickly progress can be lost when vaccination coverage declines. 

The risk of sustained transmission is further heightened by increasing population movement across borders, constraints in vaccine supply and procurement, and large mass gatherings—such as major sporting events and large religious gatherings—that can accelerate the spread of measles across countries. Upcoming events, including the 2026 FIFA World Cup, will bring millions of people together, increasing the risk of cross-border transmission. At the same time, gaps in disease surveillance and under-reporting in some areas make it harder to detect and respond to outbreaks quickly. Without urgent investment to restore vaccination coverage, strengthen health systems, and close immunity gaps, measles will continue to spread, putting vulnerable populations at risk and reversing decades of public health progress. 

The PAHO Measles Emergency Response Appeal seeks USD 10.7 million to address immediate priority health needs and implement critical interventions to protect lives and contain the ongoing multi-country measles outbreaks across the Region of the Americas. These funds will support strengthened epidemiological surveillance, expanded vaccination efforts, enhanced outbreak response capacity, and the implementation of essential prevention and control measures to reduce transmission and protect vulnerable populations.