United Nations agencies have warned that global immunisation efforts are facing growing threats due to misinformation, population growth, humanitarian crises, and funding cuts.

These challenges are putting millions of children, adolescents, and adults at increased risk of vaccine-preventable diseases.

In a joint statement issued on Thursday to mark World Immunisation Week 2025, the World Health Organisation (WHO), United Nations Children’s Fund (UNICEF), and Gavi, the Vaccine Alliance raised alarm over the growing threats to global immunisation efforts.

They called for urgent and sustained political attention and investment to safeguard decades of progress in reducing child mortality.

“Outbreaks of vaccine-preventable diseases such as measles, meningitis, and yellow fever are rising globally. Diseases like diphtheria, once nearly eradicated in many countries, are at risk of resurgence,” the agencies stated.

Dr Tedros Ghebreyesus, Director-General of WHO, highlighted that vaccines had saved more than 150 million lives over the past 50 years, yet recent funding cuts to global health were threatening these hard-won gains.

“Outbreaks of vaccine-preventable diseases are increasing worldwide, putting lives at risk and increasing the cost of disease treatment and outbreak response.

“Countries with limited resources must prioritise high-impact interventions, especially vaccines,” Ghebreyesus said.

He noted that measles cases rose to 10.3 million in 2023, marking a 20 per cent increase from the previous year.

He said that the spike reflected declines in immunisation coverage, especially following the COVID-19 pandemic.

Ghebreyesus said the agencies warned that this upward trend likely continued into 2024 and 2025, with 138 countries reporting measles cases, and 61 experiencing large-scale outbreaks—the most since 2019.

“Meningitis is also on the rise, particularly in Africa. In the first three months of 2025 alone, more than 5,500 suspected cases and nearly 300 deaths were reported across 22 countries.

“This follows nearly 26,000 cases and 1,400 deaths in 2024.

“Yellow fever cases are similarly climbing in both Africa and the Americas. In 2024, 124 confirmed cases were reported in 12 African countries. By early 2025, 131 cases were confirmed in four countries in the Americas.

“A recent WHO survey of 108 country offices—mostly in low- and lower-middle-income countries—revealed that nearly half face moderate to severe disruptions to vaccination campaigns due to reduced donor funding.

“Routine immunisation and disease surveillance are also being impacted.”

Ghebreyesus said that the number of children missing routine vaccinations continued to rise.

He said in 2023, an estimated 14.5 million children missed all their vaccine doses, up from 13.9 million in 2022 and 12.9 million in 2019.

According to him, more than half of these children live in fragile or conflict-affected countries, where healthcare access is severely limited.

UNICEF Executive Director Catherine Russell emphasised that the global funding crisis was limiting the ability to protect more than 15 million vulnerable children from measles in fragile and conflict-affected regions.

“Immunisation services, disease surveillance, and outbreak response in nearly 50 countries are already being disrupted at levels similar to the COVID-19 pandemic.

“We cannot afford to lose ground in the fight against preventable diseases,” she warned.

She highlighted the importance of continued investment in initiatives like The Big Catch-Up, inaugurated in 2023 to reach children who missed vaccines during the pandemic.

Russell also noted substantial progress, such as the near doubling of HPV vaccine coverage in Africa, which rose from 21 per cent in 2020 to 40 per cent in 2023.

She highlighted increased global access to pneumococcal conjugate vaccines, particularly in high-burden countries like Chad and Somalia.

Dr Sania Nishtar, CEO of Gavi, described the rising outbreaks of highly infectious diseases as a global concern.

“The good news is we can fight back.

“Gavi’s next strategic period includes plans to strengthen vaccine stockpiles and roll out preventive vaccination in countries most impacted by meningitis, yellow fever, and measles,” she said.

However, she cautioned that these efforts were at risk without full funding.

“We call on our donors to support our mission to protect everyone, everywhere, from preventable diseases.”