OPS Warns of Rising Measles Cases Ahead of 2026 World Cup, Urges Vaccination and Surveillance

The Pan American Health Organization (PAHO) has issued an epidemiological alert regarding the continued transmission of measles across the Region of the Americas, urging countries to strengthen vaccination efforts and surveillance systems ahead of the 2026 FIFA World Cup, which will be hosted by the United States, Canada, and Mexico.

In 2025, the Region reported 14,891 confirmed measles cases, including 29 deaths, across 13 countries, representing a 32-fold increase compared to the 466 cases reported in 2024. During the first three weeks of 2026, an additional 1,031 cases were confirmed in seven countries—Bolivia, Canada, Chile, the United States, Guatemala, Mexico, and Uruguay—with no deaths reported during that period.

Among confirmed cases with vaccination information available, 78% were unvaccinated and 11% had an unknown vaccination status. PAHO emphasized that these gaps in immunity, combined with increased population movement expected during the World Cup, heighten the risk of outbreaks, particularly in communities with suboptimal vaccination coverage.

PAHO recommends strengthening surveillance and active case finding, including laboratory diagnosis; implementing supplementary immunization activities to close immunity gaps; and ensuring a timely response to any suspected measles case. The organization also urges countries to increase the sensitivity of their surveillance systems in the context of mass gatherings involving high population mobility.

The alert highlights that measles is a highly contagious viral disease that can lead to severe complications, especially in young children, unvaccinated individuals, and those with weakened immune systems. While the Region of the Americas had previously eliminated measles in 2016, that status was lost in 2018, regained in 2024, and lost again in 2025, according to PAHO Director Dr. Jarbas Barbosa.

Dr. Barbosa noted that the return of measles in the Americas is a major setback but emphasized that it is entirely reversible through sustained public health efforts. He stressed that when one country loses its measles-free status, the entire region is affected, even if neighboring countries maintain that designation individually.

In mid-April 2026, the three host countries for the 2026 FIFA World Cup were among the four with the highest case counts in the region: Mexico reported 8,315 cases, the United States recorded 1,664, and Canada documented 733. Although case numbers showed a slight decline in the two weeks prior to the alert, PAHO cautioned that outbreaks cannot be considered in retreat until there are 12 consecutive weeks of decreasing transmission.

Last year, 32 deaths linked to measles were reported in the region, and in the first quarter of 2026 alone, 11 deaths had already been recorded, most among populations facing the greatest barriers to accessing health services. PAHO continues to call on governments to prioritize equitable access to vaccines and to intensify outreach to underserved communities.