WASHINGTON, United States (CMC) — The Pan American Health Organization (PAHO) is urging countries to intensify immunisation efforts as part of Vaccination Week in the Americas (VWA), amid concerns about the increase in measles cases in the region.

VWA will be observed from April 25 to May 2 and the PAHO call comes also amid sustained gains in vaccination coverage, which have not yet been sufficient to prevent a sharp resurgence of measles, with cases already surpassing totals recorded for all of 2025.

“The Region of the Americas has positioned itself as a global leader in immunisation. We are the first region to have eliminated polio, rubella and congenital rubella syndrome, and the only one that has recovered and improved vaccination coverage to pre-pandemic levels,” PAHO Director Dr Jarbas Barbosa told a news conference.

PAH said that between 1974 and 2024, childhood vaccination in the Americas prevented an estimated 15 million deaths among children under five, more than 1.1 billion cases of disability and nearly 28.4 billion cases of illness.

However, the PAHO director warned that “important gaps remain that we must close”.

PAHO said Vaccination Week in the Americas aims to address those gaps. Since its launch in 2002, the initiative has highlighted the importance of vaccination as a cornerstone of public health and enabled the administration of more than 1.2 billion vaccine doses across the region. This year, for the first time, the regional launch will take place in Ottawa, Canada, on April 27.

In 2024, regional coverage for the measles, mumps and rubella (MMR) vaccine reached 89 per cent for the first dose and 79 per cent for the second, while coverage for the third dose of the diphtheria, pertussis and tetanus (DPT) vaccine reached 87 per cent.

Despite this progress, more than 1.4 million children did not receive a single dose of these or other vaccines.

“These children are not numbers, they are lives, families and entire communities at risk,” Barbosa stressed.

As part of this year’s activities, 21 countries plan to administer nearly 90 million doses, including more than 80 million influenza vaccines and catch-up vaccination for 7.2 million children with incomplete or zero-dose schedules.

But the PAHO director also raised concern about the increase in measles cases in the region. The Americas were the first region in the world to eliminate measles in 2016; this status was lost in 2018, regained in 2024 and lost again in 2025.

In 2025, 14,767 confirmed cases were reported across 13 countries, nearly 32 times more than in 2024. The trend continues in 2026: as of April 5, more than 15,300 cases have already been reported, exceeding last year’s total.

Globally, more than 250,000 measles cases were reported in 2025, over half of them in Africa, the Western Pacific Region and Europe. Less than six per cent occurred in the Americas. However, in the first three months of 2026, the region accounted for 21 per cent of reported cases worldwide.

“The re-emergence of measles in the Americas is a significant setback, but one that is entirely reversible and demands decisive action,” Barbosa said,  warning measles “is not a mild disease” and can lead to serious complications such as pneumonia, encephalitis and blindness—and even death.

In 2025, around 13 per cent of those infected required hospitalisation, and 93 per cent were unvaccinated. Between 2025 and the first quarter of this year, 43 measles-related deaths have been reported in the region.

“The main challenge is not the availability of vaccines, but reaching those who remain unprotected in time,” Barbosa said, noting that low risk perception, misinformation and barriers to access have contributed to declining coverage in some populations.

Because measles is highly contagious, maintaining elimination requires coverage above 95 per cent with two doses.

“A single case can spark an outbreak if we do not achieve these levels of protection,” he warned.

PAHO is supporting countries by strengthening surveillance, rapid outbreak response and immunisation planning at local level, while also facilitating equitable access to vaccines through its Revolving Funds. In 2025 alone, these mechanisms enabled the procurement of 234 million doses with savings of nearly 50 per cent.

“Elimination is not a trophy to be stored away—it is an achievement that must be defended every day. We have stopped measles before. We can do it again,”  Barbosa said, emphasising that vaccination “is not only an individual decision, it is an act of collective solidarity”, reiterating that the region can move toward a future where vaccine-preventable diseases no longer pose a threat to public health.