Polio IHR public health emergency of international concern extended in March 2026 as wild poliovirus persists in Afghanistan and Pakistan

Summary

WHO's 44th meeting of the IHR Emergency Committee on Poliovirus, held March 4, 2026, extended the determination that Polio remains a Public Health Emergency of International Concern (PHEIC), a designation that has been in continuous effect since 2014. As of early 2026, six wild poliovirus type 1 (WPV1) cases had been confirmed for the year: two in Afghanistan (Kunar and Helmand, onset April 14 and May 7) and four in Pakistan, all genetically linked to the endemic reservoir that crosses the Afghanistan-Pakistan border. Vaccine-derived poliovirus type 2 (cVDPV2) continued circulating in the Lake Chad Basin (Nigeria, Niger, Chad) and Horn of Africa (Somalia, Ethiopia), with additional environmental detections in the wider region. A new cVDPV2 detection was confirmed in the United Kingdom on approximately January 28, 2026 through routine sewage surveillance, with no linked paralytic case identified. The committee noted that 30 countries remained at heightened risk of poliovirus transmission due to gaps in vaccination coverage or surveillance. Wild poliovirus has been eradicated from all countries except Afghanistan and Pakistan; complete eradication requires ending WPV1 transmission in those two countries, which has been the program's target for nearly a decade.

The split

WHO and GPEI framed the March 2026 assessment as evidence of sustained progress (WPV1 cases globally in single digits for 2026 so far) combined with a persistent danger concentrated in the Afghanistan-Pakistan corridor, where access for vaccinators is constrained by security conditions and by vaccine hesitancy in specific communities. Pakistani and Afghan public health officials cited the access constraints linked to Taliban-era restrictions on vaccination campaigns as the binding constraint. UK public health authorities (UKHSA) treated the environmental cVDPV2 detection with the standard protocol of intensified surveillance and a reminder to vaccination services, noting that paralytic cases had not followed previous UK environmental detections. African press in the Lake Chad Basin countries covered the cVDPV2 situation in relation to the oral poliovirus vaccine switch from trivalent to bivalent in 2016, which eliminated the type 2 seed strains in routine OPV but left vaccine-derived type 2 as a persisting risk in areas with low coverage.

By the numbers

• 6, wild poliovirus type 1 (WPV1) cases confirmed globally in 2026 (as of mid-2026)
• 2, WPV1 cases in Afghanistan (Kunar, Helmand; April and May 2026)
• 4, WPV1 cases in Pakistan in 2026
• ~30, countries at heightened risk of poliovirus transmission (IHR Emergency Committee, March 2026)
• January 28, 2026, UK environmental cVDPV2 detection (no linked paralytic case)
• 44th meeting, IHR Emergency Committee poliovirus designation, March 4, 2026
• 2014, year the poliovirus PHEIC designation began (in continuous effect since)

Why it matters

[[Polio]] is one of only two infectious diseases (the other being smallpox, which was eradicated in 1980) for which the international community has formally committed to global eradication. The persistence of WPV1 in Afghanistan and Pakistan after more than 30 years of the eradication program reflects the interaction of access constraints, political instability and vaccine hesitancy that define the final-mile eradication challenge. The cVDPV2 problem is a secondary complication: widespread use of oral poliovirus vaccine produced immunity but also introduced live-attenuated virus that can revert to neurovirulence and transmit in under-immunized populations. European environmental detections of cVDPV2 serve as a surveillance indicator for vaccination coverage gaps in high-income countries that had largely forgotten polio as a domestic concern. The PHEIC designation mandates that countries with WPV or cVDPV require travelers from affected areas to have documented polio vaccination.

What to watch

• Whether the 2026 WPV1 case count in Pakistan and Afghanistan rises above prior years or continues to trend lower
• Taliban engagement (or non-engagement) with GPEI vaccination campaigns in Afghanistan, which have had partial access restored at various points
• Whether the UK cVDPV2 environmental detection leads to identified transmission chains
• GPEI's July 2026 strategic review of the eradication timeline