Polio remains a global emergency, but wild virus cases fell by more than half in 2025

The World Health Organization's polio Emergency Committee has concluded, for the forty-fourth time since 2014, that the international spread of poliovirus still constitutes a Public Health Emergency of International Concern [s1]. The committee, which met on 14 January and issued its statement on 4 March, recommended that the temporary emergency recommendations governing cross-border travel and vaccination continue for another three months [s1].

The headline number moved in the right direction. Wild poliovirus type 1 (WPV1) caused 40 cases in 2025, down from 99 in 2024 — a reduction of roughly 60% [s1]. Nine of those cases were in Afghanistan and 31 in Pakistan, the only two countries where the wild virus remains endemic [s1]. Environmental surveillance told a similar story: 673 sewage and wastewater samples tested positive for WPV1 during the year, the large majority of them, 608, in Pakistan and 64 in Afghanistan [s1].

Where transmission is concentrated

The committee's statement singles out two areas as the epicenters of continued wild-virus circulation: Pakistan's South Khyber Pakhtunkhwa and Karachi, and southern Afghanistan [s1]. It also flagged a specific data problem in Karachi, saying campaign-quality data from that bloc "does not provide a sufficiently accurate picture" of actual vaccination coverage — a way of saying the true number of missed children is probably higher than official figures suggest [s1].

Wild poliovirus also turned up somewhere with no history of transmission: German wastewater, in October 2025. WHO linked the finding to a case detected in Afghanistan two months earlier, in August 2025 [s1]. A single imported case triggering an environmental detection thousands of miles away is a reminder of why the emergency committee treats polio as a problem that does not respect the endemic-country label — it is why the temporary recommendations include documentation requirements for international travelers coming from infected countries [s1].

The vaccine-derived side of the ledger

Wild poliovirus is only half of the current global picture. Circulating vaccine-derived polioviruses — strains that emerge when the live, weakened virus in oral polio vaccine regains the ability to spread and cause paralysis, typically in places where routine immunization coverage is low — caused 202 cases across 27 countries in 2025 [s1]. Most, 192 cases, were type 2 (cVDPV2); the rest split between type 3 (7 cases) and type 1 (3 cases) [s1].

Nigeria carried the largest share of the cVDPV2 burden, with 53 cases, or roughly 28% of the global total, followed by Ethiopia with 40 and Yemen with 30 [s1]. Two new outbreaks appeared for the first time in 2025: a cVDPV1 outbreak in Laos and a cVDPV2 outbreak in Namibia [s1] — both signs of how a single lapse in population immunity can let a vaccine-derived strain establish itself in a country with no recent history of the problem.

What the committee is asking countries to do

Beyond extending the emergency declaration itself, the committee's recommendations to member states are aimed at closing the gaps that let both wild and vaccine-derived virus persist. States experiencing active transmission are asked to declare polio interruption a national public health emergency, a designation intended to mobilize domestic resources and political attention beyond what routine immunization programs typically receive [s1]. The committee also called for mandatory documentation of polio vaccination for international travelers departing infected countries, tighter cross-border coordination on vaccination campaigns, introduction of inactivated polio vaccine (IPV) into routine immunization schedules where it is missing, and stronger surveillance systems paired with more equitable access to vaccination for hard-to-reach populations [s1].

The committee did make one distinction worth noting: it determined that the current situation, serious as it is, does not meet the threshold of a "pandemic emergency" under the International Health Regulations — a separate and higher classification [s1]. The PHEIC designation itself is unchanged from the label WHO has applied continuously since 2014, when the emergence of polio in multiple regions first triggered it.

What to watch

WHO's own eradication targets are explicit and near-term: interrupting endemic wild poliovirus type 1 transmission in 2026, and stopping cVDPV2 outbreaks by 2028 [s1]. The committee's own data suggest the wild-virus target is within closer reach than the vaccine-derived one — a 60% year-on-year drop in WPV1 cases is a meaningful trajectory, even with two endemic countries still reporting transmission. The vaccine-derived numbers point the other way: 202 cases spread across 27 countries, plus two newly seeded outbreaks in Laos and Namibia, describes a problem that is not shrinking so much as moving. Whether campaign quality in Karachi improves, and whether Nigeria's cVDPV2 burden begins to fall, will be among the clearest signals of whether the next quarterly committee statement can report progress rather than persistence.

Sources

• Statement of the Forty-fourth Meeting of the Polio IHR Emergency Committee — World Health Organization, 4 March 2026