In late September 2026, the World Health Organization's polio emergency committee gathered by video to take stock of a long campaign that has shrunk the wild poliovirus dramatically yet has not finished it. Wild poliovirus still circulates in Afghanistan and Pakistan, where a few corridors of insecurity, low immunity and uneven vaccination keep the disease alive, while vaccine-derived strains continue to flare in parts of Africa. The committee's cautious verdict, that progress is real but fragile, reflects a familiar lesson in public health: the last cases are the hardest to chase down, and th
WHO Polio Emergency Committee Warns Wild Poliovirus Transmission Persists Across Afghanistan-Pakistan Bloc
Children remain paralysed or at risk from WPV1 and cVDPV infection, with many unvaccinated due to insecurity and access gaps in Afghanistan and Pakistan.
Gains made remain fragile
Mark
Cases are down from 99 in 2024 to 29 so far in 2026. Why is the committee still worried?
Mimi
Because the decline is uneven. The South Region of Afghanistan, South Khyber Pakhtunkhwa and Karachi still have local transmission, and Peshawar and eastern Afghanistan are ticking up.
Luke
Worth saying the 2026 total of 29 is a partial-year count. It isn't a final figure.
Mark
What's the biggest obstacle in Afghanistan?
Mimi
Access. No house-to-house campaigns since October 2024, and very few women health workers, especially in the South. Site-to-site vaccination often misses younger children.
Luke
The committee says that could contribute to spread. That's a warning about risk, not a measured outcome.
Mark
And Pakistan?
Mimi
Strong political commitment and high reported coverage, but district quality varies, and South KP has the country's most intense transmission.
Luke
Note 'reported' coverage. The committee itself says district-level quality is inconsistent, so national pass rates don't tell the whole story.
Mark
What about the genetic data?
Mimi
Two clusters were split into eight, four still active in 2026, and cross-border sharing was documented in mid-2026.
Luke
What we don't know from this text is whether the 2026 interruption target will be met. The committee doesn't say.
El Pulso
- Wild poliovirus has returned with 25 new cases since May, 22 of them in Afghanistan, keeping the 2026 eradication target under pressure.
- South Afghanistan and South Khyber Pakhtunkhwa are the hot zones, where low immunity and insecurity leave gaps the virus is quick to exploit.
- With no house-to-house campaigns in Afghanistan since October 2024, teams work site to site and often miss younger children.
- Peshawar's slight rise in detections and the upward trend in eastern Afghanistan signal the risk is spreading along the northern corridor.
- Vaccine-derived poliovirus remains active across 20 countries, with DRC and Nigeria carrying most of the cVDPV2 burden, as the 2028 target approaches.
In late September 2026, the World Health Organization's polio emergency committee gathered by video to take stock of a long campaign that has shrunk the wild poliovirus dramatically yet has not finished it. Wild poliovirus still circulates in Afghanistan and Pakistan, where a few corridors of insecurity, low immunity and uneven vaccination keep the disease alive, while vaccine-derived strains continue to flare in parts of Africa. The committee's cautious verdict, that progress is real but fragile, reflects a familiar lesson in public health: the last cases are the hardest to chase down, and the children who are missed by the campaigns are the ones the virus finds.
On 30 September 2026, the World Health Organization convened the 46th meeting of its Emergency Committee on the international spread of poliovirus, held by video with the affected countries. The committee reviewed wild poliovirus type 1 and vaccine-derived strains against two goals: stopping wild transmission in 2026 and ending vaccine-derived outbreaks by 2028.
The wild virus is retreating but has not gone. Since May, 25 new cases have appeared, 22 in Afghanistan and three in Pakistan, bringing the year's total to 29. Those numbers are far below 2024 and 2025, yet the virus is still moving through the same stubborn places: the south of Afghanistan, South Khyber Pakhtunkhwa and parts of Karachi. In the south of Afghanistan, low immunity keeps transmission intense. In South Khyber Pakhtunkhwa, insecurity makes high-quality vaccination hard, though fewer children were missed in the two latest campaigns.
Some gains are real but fragile. Quality in the northern corridor has improved, but Peshawar has seen a slight rise in detections and eastern Afghanistan has trended upward, largely from infections arriving from the south. Pakistan's leadership was praised, yet district-level quality still varies, and undocumented migrants returning from Pakistan add to the strain.
Afghanistan's central difficulty is access. Without house-to-house visits since October 2024, and with very few women among vaccinators, teams often miss children, especially the youngest. The committee warned that this could let the virus spread further.
Far from the wild virus, vaccine-derived strains persist across 20 countries. The Democratic Republic of the Congo and Nigeria account for about three quarters of the cVDPV2 cases. The committee will keep watching cross-border coordination, Peshawar's detections and whether the 2026 target can still hold.
On 30 September 2026, the WHO Director-General convened the 46th meeting of the Emergency Committee on the international spread of poliovirus, held by video conference with the affected countries. The committee reviewed data on wild poliovirus type 1 (WPV1) and circulating vaccine-derived polioviruses (cVDPV), measured against two goals: interrupting endemic WPV1 transmission in 2026, and stopping cVDPV2 outbreaks by 2028. Technical updates covered Afghanistan, the Central African Republic, the Democratic Republic of Congo, Ethiopia, Pakistan, South Sudan and Sudan.
The wild poliovirus numbers are falling, but the virus is still moving. Since the committee's May 2026 meeting, 25 new WPV1 cases have been reported: 22 in Afghanistan, from the South and East Regions, and three in Pakistan, all in Khyber Pakhtunkhwa. For 2026 so far, that makes 29 cases, 25 in Afghanistan and four in Pakistan. In 2025 there were 52 cases (21 in Afghanistan, 31 in Pakistan), and 99 in 2024. Environmental surveillance has found 204 positive samples in 2026, 76 from Afghanistan and 128 from Pakistan, against 747 in 2025. Those 2025 samples included two from Germany, where no further detections were reported after the first half of October 2025.
The committee said transmission remains concentrated in three places: the South Region of Afghanistan, South Khyber Pakhtunkhwa and Karachi. The southern region of Afghanistan is the greatest concern, with intense transmission driven by low population immunity. In South Khyber Pakhtunkhwa, security and operational problems get in the way of high-quality vaccination, though the committee was encouraged that fewer children were left unvaccinated after the two most recent campaigns there. Karachi saw a significant decline in positive environmental samples in 2026, yet local transmission continues in some areas, pointing to pockets of low immunity.
There was progress to report, with caveats. In the northern corridor, linking Peshawar and Afghanistan's East Region, programme quality has improved. But Peshawar has seen a slight recent rise in detections, and the East Region has trended upward over six months, mostly from introductions out of southern Afghanistan. In the Quetta Block, positive environmental samples have declined, but the committee called those gains fragile because transmission next door in southern Afghanistan is intense, campaign quality is uneven and routine immunization coverage is low.
The genetic picture is more complicated. Diversity in the virus fell between 2020 and 2023, then rose in 2024, forcing scientists to split two genetic clusters into eight. Seven were active in 2025 and four remain active in 2026. Shared cross-border transmission was documented as recently as mid-2026.
Both countries run intensive, mostly synchronized campaigns. Afghanistan held two nationwide and five sub-national campaigns in 2025, and so far in 2026 has held one nationwide and two sub-national rounds. Pakistan held five nationwide and one sub-national campaign in 2025, and two nationwide and two sub-national so far in 2026. Both have also run targeted fractional-dose IPV campaigns in high-risk areas.
Afghanistan's central difficulty is access. House-to-house campaigns have not been carried out since October 2024 because of security concerns, so teams work site to site. Women make up very few of the vaccination workers, particularly in the South. The committee warned that this setup often misses children, especially younger ones, and could spread the virus further. In Pakistan, it praised leadership at all levels, including the Prime Minister's Office, and high reported coverage and LQAS pass rates nationally and provincially. District-level quality, though, remains variable in Quetta Block, South KP and the Central Pakistan Bloc, owing to insecurity, operational hurdles and vaccine hesitancy in some communities. South KP has the country's most intense transmission. Undocumented migrants returning from Pakistan to Afghanistan add to the difficulty.
On vaccine-derived virus, 155 cVDPV cases and 61 environmental detections were reported across 20 countries in 2026 as of 15 September: 118 cVDPV2 cases, 24 cVDPV1 and 13 cVDPV3. In 2025 the totals were 246 cases and 249 detections across 30 countries. The Democratic Republic of the Congo (52 cases) and Nigeria (36) account for about 75% of cVDPV2 cases. There were 23 unique cVDPV2 emergence groups in 2026, versus 35 in 2025.
The committee treats Afghanistan and Pakistan as a single epidemiological bloc. What to watch: cross-border coordination, Peshawar and East Afghanistan detections, and whether the 2026 interruption target holds.
Citas Notables
Afghanistan and Pakistan constitute a single epidemiological bloc, with a continued risk of cross-border transmission.— WHO Polio IHR Emergency Committee, 46th meeting
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