PAHO intensifies call to strengthen vaccination in light of rising measles cases in the Americas – PAHO/WHO
Washington, DC, September 19, 2025 (PAHO) – The Pan American Health Organization (PAHO) urges the countries of the Americas to strengthen vaccination efforts, improve surveillance and accelerate the response to the outbreak after an increase in measles cases in the region. As of September 12, 2025, 11,313 cases and 23 deaths have been confirmed in ten countries, an increase of 31 times compared to the 358 cases reported in the same period in 2024, according to the latest epidemiological update of Pah published today.
«Measles is a preventable disease thanks to vaccination, but low coverage in vulnerable communities is feeding these outbreaks,» said Dr. Daniel Salas, executive manager of the Special PAHO program on integral immunization. «Strengthening immunization, knowing that the measles vaccine is safe and highly effective, is essential to protect millions of Americas,» he added.
Ten countries have reported cases this year, with Canada (4,849 cases, 1 death), Mexico (4,553 cases, 19 deaths) and the United States (1,454 cases, 3 deaths) that represent 96% of the total cases in the region. Additional cases have been reported in Bolivia (320), Brazil (28), Argentina (35), Belize (34), Paraguay (35), Peru (4) and Costa Rica (1).
The outbreaks have mainly affected communities with low vaccination coverage or vaccination resistance. The most affected group was children under 1 year (6.6 cases per 100,000 population), followed by children from 1 to 4 years (3.6 percent). More than 71% of confirmed cases were not vaccinated, while the vaccination status was unknown in additional 18%.
The data indicates the regional transmission initially driven by imported cases, with 71% classified as importation and 16% as imported cases. This highlights the urgent need to reinforce both epidemiological surveillance and vaccination coverage.
In 2024, the region observed a slight increase in measles vaccination coverage, reaching 89% for the first dose (MMR1), compared to 87% in 2023 and 79% for the second dose (MMR2), compared to 76% the previous year. However, only 31% of countries and territories achieved MMR1 coverage equal to or greater than 95%, and only 20% reached that threshold for the second dose. In addition, 49% of the countries reported a MMR2 coverage below 80%, which underlines persistent immunization gaps.
The vaccine vaccine and limited access in vulnerable rural and urban communities remain significant barriers. To effectively prevent measles outbreaks, a population level coverage of at least 95% with both doses is required.
Worldwide, the World Health Organization (WHO) has reported 164,582 measles cases confirmed in 173 countries as of September 9, 2025, based on a total of 360,321 suspicious cases. The most affected regions are the Eastern Mediterranean (34%), Africa (23%) and Europe (18%).
PAHO recommendations
To stop the transmission, Paho urges countries A:
- Achieve vaccination coverage of at least 95% with two doses of vaccine containing sarampos in each municipality.
- Immediately vaccinate all confirmed or suspect cases contacts up to 39 years of age, ideally within the first 72 hours.
- Intensify vaccination campaigns in areas with outbreaks or at risk of propagation, and manage vitamin A to confirmed cases to reduce the risk of complications.
- Strengthen surveillance in high -risk transmission areas, borders and silent, including the discovery of active cases.
- Implement fast response plans, including trained equipment, situation rooms and adequate hospital insulation protocols.
- International travelers vaccinated without documented measles immunization, including children from 6 to 11 months as an exceptional measure, at least 10 days before traveling to areas with active transmission.
Paho also emphasizes the training of health personnel and the communities involved to combat erroneous information, using tools such as online courses available through the Pah virtual campus for public health.
