Decades of progress in immunization are under severe threat as misinformation, population growth, humanitarian crises, and funding cuts jeopardize efforts to protect millions of lives, warned the World Health Organization (WHO), UNICEF, and Gavi during World Immunization Week (April 24–30).  Once under control or near elimination, vaccine-preventable diseases such as measles, meningitis, yellow fever, and diphtheria are now resurging, placing children, adolescents, and adults at increasing risk.

Urging urgent political action and renewed investment, the agencies stressed that sustained support for immunization programs is crucial to safeguard the advances made in reducing child mortality over the past five decades.  “Vaccines have saved more than 150 million lives over the past five decades,” said WHO Director-General Dr. Tedros Adhanom Ghebreyesus. “But funding cuts to global health have put these hard-won gains in jeopardy.” Dr. Tedros emphasized that outbreaks of vaccine-preventable diseases are not only endangering lives but also increasing healthcare costs worldwide.

He called for countries with limited resources to prioritize investments in vaccines, describing them as one of the most impactful health interventions.  The resurgence of measles is of particular concern. Since 2021, measles cases have climbed steadily following declines in vaccination coverage during the COVID-19 pandemic. In 2023, an estimated 10.3 million measles cases were reported globally—a 20% increase compared to 2022.

This worrying trend likely continued into 2024 and 2025, with 138 countries reporting measles cases in the past year, and 61 countries experiencing major or disruptive outbreaks, the highest recorded in any 12-month period since 2019.  Meningitis is also making a troubling comeback, particularly in Africa. In just the first three months of 2025, over 5,500 suspected meningitis cases and nearly 300 deaths were reported across 22 countries. This follows approximately 26,000 cases and nearly 1,400 deaths in 2024.

Meanwhile, yellow fever cases are rising after years of decline, with 124 confirmed cases across 12 African countries this year alone, and fresh outbreaks also reported in the Americas, with 131 cases detected across four countries.  These disease outbreaks are unfolding against the backdrop of significant funding challenges.

A recent WHO survey across 108 country offices, mostly in low- and lower-middle-income nations, revealed that nearly half are facing moderate to severe disruptions to vaccination campaigns, routine immunization services, and access to essential supplies due to reduced donor funding. Disease surveillance, a critical tool for detecting and controlling outbreaks, has also been weakened in more than half of the countries surveyed.  At the same time, the number of children missing routine vaccinations has been steadily increasing. In 2023, an estimated 14.5 million children missed all their routine vaccine doses, up from 13.9 million in 2022 and 12.9 million in 2019.

More than half of these children live in countries facing conflict, fragility, or instability, where basic healthcare access is often disrupted.  “The global funding crisis is severely limiting our ability to vaccinate over 15 million vulnerable children in fragile and conflict-affected countries against measles,” said UNICEF Executive Director Catherine Russell.

She warned that the disruption of immunization services and disease surveillance in nearly 50 countries mirrors the setbacks witnessed during the COVID-19 pandemic, posing a serious risk to global health.  In response to these challenges, WHO, UNICEF, Gavi, and partners have been working to expand vaccine access and strengthen immunization systems through primary healthcare initiatives.

Despite rising obstacles, vaccines continue to save nearly 4.2 million lives every year against 14 diseases, with almost half of these lives saved in the African Region.  Efforts to combat meningitis have shown remarkable success, with the virtual elimination of meningitis A in Africa’s "meningitis belt." A new vaccine protecting against five strains of meningitis offers hope for broader protection, with plans underway to expand its use in outbreak response and prevention. Progress in yellow fever control had been notable through increased routine vaccination and emergency stockpiles, although recent outbreaks have highlighted ongoing vulnerabilities in regions with low immunization coverage. 

Other encouraging developments include the nearly doubling of HPV vaccine coverage in Africa between 2020 and 2023—from 21% to 40%—marking a significant step toward the elimination of cervical cancer. Global coverage of pneumococcal conjugate vaccines has also increased, particularly in the South-East Asia Region, and countries like Chad and Somalia, both with high disease burdens, have introduced the vaccine into their national programs. 

Additionally, the introduction of malaria vaccines at a sub-national level in nearly 20 African countries is laying the groundwork for saving an estimated half a million additional lives by 2035, as broader adoption and scale-up efforts take root.  As World Immunization Week 2025 unfolds, health leaders emphasize that continued investment in immunization programs is not just a necessity but a global imperative.

Sustained efforts to rebuild and strengthen immunization systems, improve surveillance, and ensure equitable access to vaccines are essential to protect the progress achieved so far and prevent a resurgence of deadly diseases.  “We cannot afford to lose ground,” Russell emphasized. “Immunization is one of humanity’s greatest success stories—and it must remain a global priority.”