Public Health Risk Assessment Related to Measles: Implications for the Americas Region, v3 (following mass gathering events) - 5 August 2026

This Rapid Risk Assessment (RRA) replaces the one published on 18 February 2026, and aims to assess the current public health risk in the Americas Region associated with the increase in measles outbreaks and cases reported during 2026 in several countries within and outside the Region, the high mobility of people related to various types of mass gathering events (sports, music, religious, cultural, and others) and tourism activity that increased during the current holiday season (June–August).

Although the public health risk associated with measles in the Americas Region continues to be classified as Very High, the factors underlying this classification differ from those considered in the assessment conducted on 18 February 2026.

The public health risk associated with measles in the Americas Region, especially in countries with suboptimal vaccination coverage, continues to be classified as “Very High” with a “High” confidence level based on available information.