WHO Keeps Polio Emergency in Place as Virus Survives Low Season in Afghanistan and Pakistan

Geneva, Switzerland – August 25, 2026

The effort to eradicate polio will remain under the highest level of international alert, after the World Health Organization's Emergency Committee concluded that the virus continues to pose a risk of cross-border spread and should stay classified as a Public Health Emergency of International Concern (PHEIC).

The determination, published August 25, 2026 following the 45th meeting of the Polio International Health Regulations (IHR) Emergency Committee, extends temporary recommendations for another three months for countries reporting poliovirus detections. The committee, convened by the WHO Director-General on May 14, 2026, reviewed epidemiological data through April 30, 2026.

It found that while the trajectory of wild poliovirus type 1 (WPV1) cases is declining, transmission survived the low season in the most entrenched reservoirs — the South Region of Afghanistan, South Khyber Pakhtunkhwa and Karachi in Pakistan — and that circulating vaccine-derived poliovirus type 2 (cVDPV2) remains entrenched in the Lake Chad Basin and Horn of Africa.

Why the Emergency Stays

The committee concluded unanimously that the risk of international spread persists, and that the event does not meet the criteria for a pandemic emergency — a higher alert level introduced under amended IHR provisions that entered into force in September 2025.

The reasoning centers on geography, immunity gaps and mobility.

Wild poliovirus remains confined to Afghanistan and Pakistan, which the committee treats as a single epidemiological block. Yet intense transmission in the southern Afghanistan-Quetta Block corridor and the central corridor spanning northwest Pakistan and southeast Afghanistan, plus Karachi, has continued without break from October 2025 through April 2026 — the period when cooler temperatures and lower movement typically suppress transmission.

Molecular epidemiology shows that after genetic diversity declined between 2020 and 2023, diversity rose again in 2024, with two clusters splitting into eight; four remain active in 2026. Evidence of shared cross-border transmission was documented as recently as the first quarter of 2026.

"The committee noted with concern the continued WPV1 transmission in both endemic countries, which persisted throughout the most recent low transmission season, particularly along the southern and central cross-border epidemiological corridors, as well as in Karachi." — Statement of the Forty-fifth Meeting of the Polio IHR Emergency Committee, WHO, August 25, 2026

For vaccine-derived viruses, the picture is broader. As of April 30, 2026, 32 cVDPV cases and 27 environmental detections were reported globally across 12 countries in 2026, with 28 of those cases type 2. In 2025, 238 cVDPV cases were reported across 30 countries. Nigeria accounted for the largest share — 66 cases in 2025 and 14 in 2026 — representing half of the global type 2 burden this year.

Campaign Quality and Access Gaps

Both Afghanistan and Pakistan continue intensive, largely synchronized campaigns, but the committee flagged persistent quality issues.

In Afghanistan, house-to-house vaccination has not been implemented since October 2024 due to security concerns. Campaigns rely on a site-to-site strategy, which often fails to reach younger children. Participation of women health workers remains very low, especially in the South Region, further limiting coverage. The committee expressed concern that without house-to-house access, geographic spread within Afghanistan and beyond remains possible.

In Pakistan, the committee acknowledged strong political leadership and high reported coverage at national and provincial levels, but noted district-level variability in Quetta Block, South Khyber Pakhtunkhwa and Central Pakistan due to insecurity in Khyber Pakhtunkhwa and Balochistan. An estimated 250,000 children in South Khyber Pakhtunkhwa remain unreached. Early gains in Karachi after an audit — with declining environmental detections and improving lot quality assurance sampling — remain fragile.

Afghanistan's surveillance system also faced disruption when the Afghanistan–Pakistan land border closed from October 12, 2025 to early January 2026, preventing shipment of acute flaccid paralysis and environmental samples to the Regional Reference Laboratory in Islamabad. Aerial shipment resumed in the second week of January 2026, and WHO is now coordinating contingency testing capacity with other regional laboratories.

Vaccine-Derived Strains Expand

Thirteen cVDPV2 emergence groups were detected in 2026, all continuations from 2025, with no new emergences this year. More than 2 billion doses of novel oral polio vaccine type 2 (nOPV2) have been administered since 2021, associated with 42 emergences. The committee noted nOPV2 demonstrates significantly greater genetic stability and lower risk of reversion than Sabin OPV2, and that more than 80% of affected countries interrupted outbreaks with three or fewer supplementary immunization activities using nOPV2.

However, cVDPV1 and cVDPV3 are trending upward from low levels. In 2025, three cVDPV1 cases were reported alongside environmental outbreaks in Djibouti and Israel, with two cases in South Sudan in 2026. Nigeria reported co-circulation of types 2 and 3 in 2026, following earlier co-circulation of types 1 and 2 in Algeria, DR Congo, Djibouti and Israel.

The committee highlighted acute challenges in Yemen's northern governorates, where more than 4.5 million children under five remain without access to an oral polio vaccine response due to insecurity, leaving a large susceptible pool. A significant backlog of stool specimens from Yemen also awaits testing. In Somalia, more than 450,000 children in South and Central regions were missed during campaigns.

Temporary Recommendations Extended

The committee extended temporary recommendations under the IHR for three categories of states, based on data as of April 30, 2026:

States with local transmission must ensure residents and long-term visitors receive a bivalent OPV or IPV dose between four weeks and 12 months before international travel, provide International Certificates of Vaccination, and restrict travel for those without proof at departure points. States previously infected within the last 24 months but now without detections remain on a 12-month watch list.

The committee also stressed a bloc approach to cross-border coordination, particularly around the Afghanistan–Pakistan border, the Lake Chad Basin, and the Horn of Africa, and called for whole-of-government engagement down to district level.

Funding Shortfall Threatens Gains

A nearly 30% financial shortfall now confronts the Global Polio Eradication Initiative, compounded by funding constraints at WHO, international partners and national governments amid rising transport and fuel costs.

The committee urged donors to increase support and governments to prioritize polio eradication in domestic budgets, warning that surveillance quality — the early warning system for the entire programme — is at risk if resources thin further. It also condemned attacks on health workers and expressed condolences to families of workers killed during vaccination activities.

The next Emergency Committee review is expected in approximately three months, when members will again assess whether the PHEIC should be continued, modified, or lifted.

Source: WHO Statement of the Forty-fifth Meeting of the Polio IHR Emergency Committee, August 25, 2026. WHO IHR Emergency Committee deliberations May 14, 2026. ReliefWeb / WHO News Release.