The Pan American Health Organization (PAHO) is calling on countries across the region to intensify immunization campaigns during Vaccination Week in the Americas, running from April 25 to May 2, amid a sharp resurgence of measles cases.
The appeal comes as health officials warn that measles infections have already surpassed the total number recorded in 2025, despite long-term gains in vaccination coverage across the Americas.
Speaking at a briefing in Washington, PAHO Director Jarbas Barbosa said the region has long been a global leader in immunization, achieving historic milestones such as the elimination of polio, rubella, and congenital rubella syndrome.
“The Region of the Americas has positioned itself as a global leader in immunization,” Barbosa said, while cautioning that “important gaps remain that we must close.”
PAHO estimates that childhood vaccination efforts over the past five decades have prevented millions of deaths and cases of illness and disability. However, the agency says coverage gaps continue to leave vulnerable populations at risk.
Between 1974 and 2024, immunization is credited with preventing an estimated 15 million deaths among children under five across the region. Still, more than 1.4 million children remain unvaccinated or under-vaccinated.
For measles, mumps and rubella (MMR), regional coverage in 2024 reached 89% for the first dose and 79% for the second—levels still below what is needed to fully prevent outbreaks.
Measles resurgence raises alarm
Health officials are particularly concerned about the sharp rebound in measles. The Americas first eliminated the disease in 2016, lost that status in 2018, regained it in 2024, and then lost it again in 2025.
In 2025 alone, nearly 14,800 cases were reported across 13 countries—about 32 times higher than the previous year. As of early April 2026, more than 15,000 additional cases have already been recorded.
Globally, more than 250,000 measles cases were reported in 2025, with the Americas accounting for less than 6% of those cases. However, early 2026 data shows the region now representing a much larger share of global infections.
Barbosa warned that measles is highly contagious and can lead to severe complications, including pneumonia, encephalitis, blindness, and death. He noted that most recent cases have occurred among unvaccinated individuals, with hospitalization rates reaching 13% in 2025.
Vaccination Week push
Vaccination Week in the Americas, launched in 2002, has become one of the region’s largest public health campaigns, resulting in more than 1.2 billion vaccine doses administered over the years.
This year’s campaign will include the delivery of nearly 90 million doses across 21 countries, including influenza vaccines and catch-up doses for millions of children with incomplete immunization schedules.
For the first time, the regional launch will take place in Ottawa, Canada.
PAHO emphasized that maintaining measles elimination requires sustained coverage above 95% with two doses of the vaccine.
“The re-emergence of measles in the Americas is a significant setback, but one that is entirely reversible,” Barbosa said, adding that misinformation, access barriers, and low risk perception are contributing to declining coverage in some communities.
He also stressed that vaccination is a collective responsibility rather than an individual choice.
“Elimination is not a trophy to be stored away—it is an achievement that must be defended every day,” he said.
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