Washington, D.C. – The Pan American Health Association (PAHO) issued an epidemiological alert today, February 4, 2026, regarding a sharp increase in measles cases across the Americas, a worrying reversal of decades of progress toward regional elimination of the disease. Driven by declining vaccination rates and persistent immunity gaps, reported cases surged too nearly 15,000 in 2025-a 32-fold increase from the previous year-and continue to climb in early 2026, with Mexico and the United States accounting for the majority of new infections. PAHO is urging swift action from Member States to bolster surveillance, vaccination campaigns, and outbreak response plans to protect populations and prevent further spread.
Washington, D.C., February 4, 2026 – The Pan American Health Organization (PAHO) has issued a new epidemiological alert regarding measles in the Americas, urging countries to strengthen surveillance, vaccination efforts, and rapid response strategies to halt transmission and protect vulnerable populations. This alert comes as measles cases continue to rise across the region, posing a significant public health concern.
The alert, released on February 3, 2026, highlights the ongoing presence of cases and outbreaks in multiple countries. A sustained increase in cases was observed throughout 2025 compared to the previous five years, and this trend appears to be continuing into 2026.
PAHO recommends bolstering surveillance through active case finding, including laboratory diagnosis, and implementing supplementary immunization activities to address gaps in immunity. A prompt response to any suspected case is also crucial, according to the organization.
Epidemiological Situation in the Region
In 2025, the region reported 14,891 confirmed measles cases, including 29 deaths, across 13 countries: Argentina (36 cases), Belize (44 cases), Bolivia (597 cases), Brazil (38 cases), Canada (5,436 cases, including 2 deaths), Costa Rica (1 case), El Salvador (1 case), the United States (2,242 cases, including 3 deaths), Guatemala (1 case), Mexico (6,428 cases, including 24 deaths), Paraguay (49 cases), Peru (5 cases), and Uruguay (13 cases). This represents a 32-fold increase compared to the 466 cases recorded in 2024.
During the first three weeks of 2026, an additional 1,031 measles cases were confirmed in seven countries – Bolivia (10), Canada (67), Chile (1), the United States (171), Guatemala (41), Mexico (740), and Uruguay (1) – with no deaths reported. This figure marks a 43-fold increase compared to the 23 cases reported during the same period in 2025.
Available data indicates that 78% of confirmed cases with available information were unvaccinated, and vaccination history was unknown in 11% of cases. While the majority of cases occurred in adolescents and young adults, the highest incidence rates were observed in children under one year old, followed by those aged 1 to 4 years and 5 to 9 years. These findings underscore the importance of ensuring complete vaccination schedules and additional protective measures during outbreaks.
Globally, the World Health Organization (WHO) reported more than 552,000 suspected measles cases in 179 countries during 2025, with approximately 45% (247,623) confirmed. This reflects a global resurgence of the disease amid persistent immunization gaps.
Vaccination Coverage and Immunity Gaps
Regional measles, rubella, and mumps (MMR) vaccination coverage in the Americas showed a slight increase from 2023 to 2024 (from 87% to 89% for the first dose and from 76% to 79% for the second dose), but remains below the 95% threshold recommended to prevent outbreaks. Only 33% of countries and territories in the region achieved 95% or higher coverage with the first dose, and just 20% reached that goal with the second dose. An estimated 1.5 million children did not receive any dose of the MMR vaccine in 2024.
PAHO emphasized that measles is highly contagious but preventable through timely vaccination with two doses of the MMR vaccine. In countries experiencing active outbreaks, the organization reiterated the need to intensify vaccination campaigns, actively search for cases, and respond quickly to interrupt transmission. Maintaining high vaccination rates is critical to preventing the spread of this potentially serious illness.
For all countries in the region, PAHO highlighted the importance of closing coverage gaps, maintaining sensitive and timely surveillance, and protecting travelers through vaccination, particularly when traveling to areas with active transmission.
With the FIFA World Cup 2026 and other mass gatherings expected to involve significant population movement, PAHO recommends that countries enhance the sensitivity of their surveillance systems through active case finding to promptly detect the presence or absence of measles and rubella cases.
PAHO will continue to monitor the measles situation and update its recommendations based on evolving epidemiological data.
