Polio remains a public health emergency of international concern despite a continued decline in case numbers, according to the World Health Organization’s (WHO) Director-General report presented to the Executive Board.

The report warns that progress toward eradication remains fragile. Some 38 cases of wild poliovirus type 1 had been reported globally by 22 October 2025, down from 62 during the same period in 2024. All cases occurred in Afghanistan and Pakistan, the only two countries where wild poliovirus remains endemic.

Environmental sampling has continued to detect the virus beyond core transmission areas, including during the low-transmission season, suggesting silent spread even where no clinical cases are immediately visible.

Transmission concentrated in endemic reservoirs

Wild poliovirus type 1 persists in a small number of reservoirs, particularly in southern Afghanistan, and the southern area of Khyber Pakhtunkhwa in Pakistan, the report notes. 

In Afghanistan, operational and communication strategies are being adjusted to improve coverage. Supplementary immunization improved markedly in the eastern region in early 2025, contributing to reductions in transmission. Vaccination teams continue to use site-to-site approaches in the south, supported by transit posts and advocacy for house-to-house vaccination to reach missed children.

Pakistan is implementing the Polio National Emergency Action Plan 2024–2025 with a phased strategy aimed at restoring an emergency posture, closing operational gaps and sustaining high immunity. While high-level political commitment and intensified supervision have improved performance, subprovincial variation persists in parts of Khyber Pakhtunkhwa, Quetta and Karachi.

Both countries are applying risk-categorization models to identify and reach migrants, mobile groups and other missed children, while strengthening coordination along virus corridors and addressing surveillance gaps. Microplanning, targeted campaigns, fractional-dose inactivated poliovirus vaccine and expanded subnational surveillance are part of these efforts.

The Global Polio Eradication Initiative (GPEI), which leads implementation with national authorities, says its 2026 Action Plan will prioritize the low-transmission season to interrupt remaining chains of spread and close immunity gaps among persistently under-immunized populations.

Vaccine-derived poliovirus outbreaks in low-coverage areas

Beyond the two endemic countries, circulating vaccine-derived poliovirus remains a persistent challenge where routine immunization coverage is weak.

WHO reported 151 cases of circulating vaccine-derived poliovirus type 2 across 13 countries as of late October 2025, compared with 182 cases across 16 countries a year earlier. Despite the decline, transmission continues in northern Nigeria, the Lake Chad Basin, the Horn of Africa, particularly south and central Somalia, Ethiopia and Yemen.

Health experts say these outbreaks occur when weakened strains of the oral polio vaccine circulate for prolonged periods among under-immunized children, allowing the virus to mutate and spread.

Some countries have recorded progress. Madagascar’s outbreak of circulating vaccine-derived poliovirus type 1 was declared closed in May 2025. In the Democratic Republic of the Congo, cases have fallen sharply in recent years following targeted responses, dropping to a single case in 2025. 

Limited detections of circulating vaccine-derived poliovirus type 3 were reported in Guinea, Cameroon and Chad, with outbreak responses underway.

New environmental detections, including in Papua New Guinea and several European countries, underscore the risk of international spread through travel, population movement and surveillance gaps.

Vaccination tools and integration expand

While the standard oral polio vaccine remains the primary tool in eradication efforts, new products include the expanded use of the novel oral polio vaccine type 2 and combination formulations.

With support from Gavi, the vaccine alliance, Senegal and Mauritania became the first countries to introduce the hexavalent vaccine into routine immunization schedules this year.

WHO partners are also emphasising the integration of polio activities into broader health services. Coordination between GPEI, the Essential Programme on Immunization and Gavi has been strengthened to reach zero-dose children with multiple vaccines and to align polio assets with routine immunization systems.

Addressing the Executive Board, a Gavi representative urged countries to promote integrated approaches to reaching zero-dose and under-vaccinated children with life-saving vaccination and primary health care, particularly in humanitarian and complex emergency settings, and to accelerate the transition of polio programme infrastructure into national systems to ensure long-term resilience.

Humanitarian pressures complicate delivery

In the Eastern Mediterranean Region, which includes both the endemic countries, ongoing crises continue to strain health services. 

Regional Director Hanan Balkhi told the board that the region carries nearly half of the world’s humanitarian burden and accounted for 40% of attacks on health care last year.

She said WHO responded to 62 outbreaks in 2025 and delivered supplies to crisis settings, including Gaza and Sudan, but funding cuts have reduced the regional health emergency workforce by about half. 

Millions of treatments are now at risk, while clinic closures in Afghanistan and disruptions in Sudan have limited access to essential services.

Cross-border collaboration between Pakistan and Afghanistan continues, supported by regional oversight and diplomatic engagement, to sustain polio eradication activities.

Although the Polio Eradication Strategy has been extended through 2029, financing remains a constraint. Donors have pledged $ 4.7 billion of the $ 6.9 billion required, leaving a $ 2.2 billion shortfall.

The Director-General’s report cautions that sustained political commitment, stronger routine immunization systems and adequate resources will be essential to interrupt remaining transmission and secure a lasting polio-free world.

Image Credits: GPEI, RAJA IMRAN BAHADR / Unsplash..