WHO Extends Polio Global Health Emergency, Stops Short of Pandemic Label

WHO keeps polio at highest alert

GENEVA — The World Health Organization has extended the world’s longest-running global health emergency, keeping the international spread of poliovirus under its highest alert, but in a pointed move after the COVID-19 pandemic it stopped short of calling polio a new pandemic.

In a statement released March 4, WHO said its Emergency Committee on polio had “unanimously concluded that the risk of international spread of polioviruses continues to constitute a Public Health Emergency of International Concern (PHEIC)” and recommended maintaining temporary measures for at least another three months. The committee also “unanimously concluded that the event does not constitute a pandemic emergency.”

On March 1, WHO Director-General Tedros Adhanom Ghebreyesus accepted that advice, formally determining that the current poliovirus situation “continues to constitute a public health emergency of international concern with respect to wild poliovirus type 1 (WPV1) and circulating vaccine-derived poliovirus (cVDPV), and does not constitute a pandemic emergency.”

The decision underscores a delicate balance for global health authorities: maintaining heightened vigilance against a virus that still paralyzes children in some of the world’s most fragile settings, while avoiding language that could trigger pandemic fears or political backlash.

A long-running emergency under new rules

Polio has been classified as a PHEIC since May 2014, when surging international spread from a handful of hotspots threatened to unravel decades of eradication gains. It is currently the only disease under that designation.

New rules adopted by member states in 2024 created a separate, higher category of “pandemic emergency,” intended for crises on the scale of COVID-19. This is the first time the new category has been explicitly weighed in a polio decision.

Where polio is still spreading

Wild poliovirus remains endemic in two countries — Afghanistan and Pakistan — but related vaccine-derived strains are circulating or have recently circulated in more than two dozen others, from Gaza and Yemen to Namibia, Papua New Guinea and parts of Europe.

From Jan. 1 to Dec. 31, 2025, 40 cases of paralysis caused by wild poliovirus type 1 were reported worldwide, according to data presented to the committee: nine in Afghanistan and 31 in Pakistan. That was down from 99 cases in 2024, continuing a long-term decline that has reduced global polio incidence by more than 99% since the late 1980s.

Yet viruses continue to show up in far more places through environmental surveillance, which tests sewage for silent transmission. In 2025, WHO recorded 673 wastewater samples positive for WPV1, including 64 in Afghanistan, 608 in Pakistan and one in Germany. The German sample, detected in October in wastewater and linked genetically to strains circulating in Afghanistan, did not result in any reported paralysis but drew attention to the risk of reintroduction into countries long considered polio-free.

“These events reaffirm that polio continues to pose a global threat until complete eradication is achieved,” the committee said.

Operational and political hurdles in Pakistan and Afghanistan

Inside the two endemic countries, the challenges are increasingly operational and political rather than technical.

Pakistan

In Pakistan, wild poliovirus was detected in environmental samples “across all four major provinces,” with particularly intense transmission in the south of Khyber Pakhtunkhwa province, the committee reported. There, health officials estimate more than 250,000 children are being missed by vaccination campaigns, largely because of insecurity, access constraints and mistrust.

Karachi, Pakistan’s largest city, remains another concern. Despite high reported vaccination coverage, the virus continues to be found in sewage. An audit cited by the committee concluded that “campaign quality and data are over-estimating coverage,” suggesting that many children in densely populated urban areas are still being missed.

Vaccination teams in Pakistan also face security threats. Local authorities have reported repeated attacks on polio workers and their police escorts in recent years, including the killing of an officer guarding a vaccination team in December.

Afghanistan

In Afghanistan, the virus is concentrated in the south, with the eastern region seeing fewer cases and detections in 2025. The committee described “intense transmission” in southern provinces and raised particular concern about how vaccination campaigns are being carried out.

Since October 2024, authorities there have not allowed house-to-house vaccination drives, relying instead on fixed “site-to-site” points such as clinics and markets. The committee warned that this approach, combined with “very low participation of women health workers,” means many younger children are likely being missed, especially in conservative communities where women are less able to bring children to public sites.

Vaccine-derived poliovirus remains a major threat

Beyond the endemic countries, much of the risk now comes from vaccine-derived polioviruses, or cVDPVs. These strains originate from the weakened live virus used in oral polio vaccines. In under-immunized populations, that virus can circulate long enough to genetically drift back toward a form that can cause paralysis.

Type 2 cVDPV has been the most problematic in recent years. In 2025, at least 13 countries reported cVDPV2 cases, and sewage or clinical detections occurred in many more. Outbreaks have flared in conflict zones such as Gaza and Yemen and in regions with weak health systems across the Sahel and Horn of Africa.

Other vaccine-derived types are also reappearing. In 2025, WHO documented cVDPV1 transmission in countries including Algeria, the Democratic Republic of Congo, Djibouti, Israel and Laos, and cVDPV3 outbreaks in Cameroon, Chad and Guinea.

WHO officials emphasized that newer tools are helping. A modified vaccine, known as novel oral polio vaccine type 2 (nOPV2), has shown “significantly greater genetic stability” and a much lower risk of reverting to a dangerous form, according to the committee. More than 80% of countries using nOPV2 have interrupted cVDPV2 outbreaks after three or fewer rounds of supplementary immunization.

Travel measures, surveillance, and a funding gap

To limit international spread, WHO renewed a set of temporary recommendations under the International Health Regulations (IHR), the legal framework that governs how countries respond to cross-border health threats.

Countries with wild poliovirus or cVDPV1 or cVDPV3 and a risk of exporting the virus are urged to:

• Maintain polio as a national public health emergency.
• Ensure that all residents and long-term visitors who plan to travel internationally receive a dose of polio vaccine four to 12 weeks before departure.
• Issue an International Certificate of Vaccination or Prophylaxis documenting that dose.
• Restrict international travel by residents who do not have proof of recent polio vaccination.

States with cVDPV2 detections are told to investigate quickly, request vaccine from the global nOPV2 stockpile if needed and strengthen both routine immunization and environmental surveillance. Those with evidence of local transmission are encouraged to promote pre-travel vaccination in a similar way.

The committee also drew attention to a widening financial gap. It said the Global Polio Eradication Initiative — a partnership led by WHO and major donors including UNICEF, the U.S. Centers for Disease Control and Prevention, Rotary International, the Bill & Melinda Gates Foundation and Gavi, the Vaccine Alliance — is facing an estimated funding shortfall of nearly 30%.

That shortfall “poses a substantial risk to all programme components, including the maintenance of sensitive poliovirus surveillance,” the committee warned. The initiative has already extended its eradication strategy, now aiming for certification of wild poliovirus eradication by the end of 2027 and elimination of cVDPV2 by 2029.

Pandemic sensitivities after COVID

The backdrop is politically charged. Amendments to the IHR, adopted by the World Health Assembly in 2024 and in force since September 2025, expanded obligations around reporting outbreaks, sharing countermeasures and recognizing both digital and paper vaccination certificates. Some governments, including the United States, have pushed back on parts of the package, citing concerns about national sovereignty and overreach by international bodies.

WHO’s explicit statement that polio does not meet the bar for a “pandemic emergency” reflects those sensitivities. Under the amended rules, such a declaration would signal not only a serious international event but also widespread, sustained global transmission at a scale approaching COVID-19.

For now, health officials say, polio is a very different kind of threat: scattered, often silent, but persistent. It is kept in check by a vast apparatus of vaccinators, laboratories and surveillance networks — and vulnerable to any weakening of that system.

As the emergency enters its 13th year, WHO’s message blends warning and cautious optimism: the virus is closer than ever to eradication, the agency says, but until the last chains of transmission are broken in the remaining strongholds and outbreaks are halted elsewhere, the world will continue to live under a “temporary” emergency that has already spanned more than a decade.