Washington, DC, February 4, 2026 (PAHO) – The Pan American Health Organization (PAHO) issued a new epidemiological alert on measles in the region of the Americas, in which it calls on countries to intensify epidemiological surveillance, vaccination and rapid response activities to outbreaks to interrupt transmission and protect vulnerable populations.
The alert, published yesterday, highlights the persistence of cases and outbreaks in several countries in the region, in a context of sustained increase in cases during 2025 compared to the last five years, a trend that appears to continue in 2026.
PAHO recommends strengthening surveillance and active case search, including laboratory diagnosis, implementing complementary vaccination activities to close immunity gaps, and ensuring a timely response to any suspected case.
Epidemiological situation in the region
In 2025, the region reported 14,891 confirmed cases of measles, including 29 deaths, in 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), 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 total represents a 32-fold increase compared to the 466 cases recorded in 2024.
In the first three weeks of 2026, an additional 1,031 cases of measles were confirmed in seven countries—Bolivia (10), Canada (67), Chile (1), the United States (171), Guatemala (41), Mexico (740), and Uruguay (1)—with no reported deaths. This total represents a 43-fold increase compared to the 23 cases reported in the same period in 2025.
The available evidence indicates that, among the confirmed cases with available information, 78% were not vaccinated and in 11% the history of vaccination was unknown. Although the highest proportion of cases was recorded in adolescents and young adults, the highest incidence rates were observed in children under one year of age, followed by children aged 1 to 4 years and 5 to 9 years, which reinforces the need to guarantee complete vaccination schedules and additional protective measures in outbreak contexts.
Globally, the World Health Organization (WHO) reported that during 2025 more than 552,000 suspected cases of measles were reported in 179 countries, of which nearly 45% (247,623) were confirmed, reflecting a global resurgence of the disease in a context of persistent immunization gaps.
Vaccination coverage and immunity gaps
Regional vaccination coverage with the measles, rubella and mumps (MMR) vaccine in the Americas showed a slight increase in 2024 compared to 2023 (from 87% to 89% for the first dose and from 76% to 79% for the second), but remains below the 95% recommended to prevent outbreaks. Only 33% of the countries and territories in the region reached 95% or more coverage with the first dose and only 20% achieved that goal with the second dose. It is estimated that 1.5 million children will not receive any doses of this vaccine in 2024.
PAHO stressed that measles is highly contagious, but preventable through timely vaccination with two doses of the MMR vaccine. In countries with active outbreaks, he reiterated the need to intensify vaccination, active case finding and rapid response to interrupt transmission.
At the same time, for all countries in the region, he highlighted the importance of closing coverage gaps, maintaining sensitive and timely surveillance, and protecting travelers through vaccination, especially when they go to areas with active transmission.
In the context of the 2026 Soccer World Cup and other massive events with high mobility of people, PAHO recommends that countries increase the sensitivity of their surveillance system by implementing active searches, in order to timely detect the absence or presence of cases of measles and rubella.
PAHO will continue to monitor the measles situation and update recommendations based on epidemiological evolution.
