Since the Global Polio Eradication Initiative began in 1988, wild poliovirus types 2 and 3 have been eradicated and polio cases have fallen by more than 99.9%. But wild poliovirus type 1 (WPV1) is still endemic in Afghanistan and Pakistan, which share a 1,600-mile (2,600-km) border. This CDC report covers Afghanistan from January 2023 to September 2024.
Cases
| Period | WPV1 cases |
|---|---|
| 2021–2022 | 6 (Southeast and Northeast regions) |
| 2023 | 6 — all in Nangarhar province, East Region |
| 2024, to September 30 | 23 — the most in four years, about four times 2023's total |
Wild poliovirus type 1 cases by month of paralysis onset, Afghanistan, January 2020–September 2024 (91 cases). CDC / MMWR
The 2024 cases came from Kandahar (14), Helmand (6) and Uruzgan (1) in the South, and Nuristan and Kunar (1 each) in the East. The children were younger — mean age 39 months, against 79 in 2023 — and less vaccinated: three had never had a single oral polio vaccine (OPV) dose.
Reported wild poliovirus type 1 polio cases by region, province and period, Afghanistan, January 2023–September 2024. CDC / MMWR
Sewage testing found WPV1 in 62 samples from eight provinces in 2023 (42 in Nangarhar) and 85 from ten provinces in January–September 2024 — now led by the South (Kandahar 35, Helmand 22).
A hard setting
Afghanistan has 8 regions, 34 provinces and 400 districts. Since the Taliban took control in August 2021 — which at first opened up access for vaccination — the humanitarian crisis has deepened: a stagnant economy, food insecurity, poor water and sanitation, limited health care, and growing restrictions on women. From October 2023 to early 2024, about 1 million Afghans were forced back from Pakistan; 44% settled in the South, mostly Kandahar, and 26% in the East, mostly Nangarhar — the two provinces that are Afghanistan's historical polio reservoirs and had most of the cases.
Women matter to vaccination: in Afghanistan, women may enter homes to vaccinate young children, but men who are not close relatives may not. Ever tighter limits on women's rights and movement have curbed their work as vaccinators and their ability, as caregivers, to take children out for vaccines.
Door to door — then not
House-to-house campaigns reach far more children than fixed posts or sites at mosques, where caregivers must bring their children.
| Campaign coverage (post-campaign surveys) | Fixed posts | Mosques | House to house |
|---|---|---|---|
| 2023 | 68–75% | 68–81% | 90–97% |
| 2024 | 73–85% | — | 90–98% |
From 2021 the authorities progressively lifted limits on door-to-door work. In June 2024 they allowed nationwide house-to-house access for the first time in about 7 years; the share of districts vaccinating door to door rose from 72–85% to 96–99%, and in the South Region, where fixed sites alone had reached as few as 19% of children, coverage rose to 89–91%. Then the authorities abruptly reversed the decision and allowed only fixed posts. The September campaign was postponed while the program worked out how to make fixed sites better.
Routine vaccination is improving but low: in 2023, 68% of 1-year-olds had three doses of bivalent OPV (56% in 2021, 61% in 2022) and 45% had two doses of inactivated polio vaccine (IPV) (30% and 43%). In 2023 the program ran 13 campaigns for children under 5; OPV was also given to travelers of all ages at the Torkham and Friendship Gate border crossings — about 1.7 million people from January 2023 to September 2024 — and the two countries coordinated and synchronized campaigns.
Surveillance gaps
The acute flaccid paralysis surveillance network grew in 2024 to 2,078 active sites, 3,315 passive sites and 50,409 community volunteers, and met the global performance targets. Yet genetic sequencing found six "orphan" viruses — more than 1.5% different from their closest known relative — and 18 others more than 1.1% different, pointing to undetected cases among undervaccinated children. The main virus cluster, YB3A4A, confined to the East in 2023, spread along the southern corridor to Kandahar and Helmand in 2024.
What is needed
House-to-house vaccination works best, and limiting campaigns to other methods jeopardizes eradication. Reaching every child needs nationwide door-to-door campaigns and a stronger routine immunization program, and stopping transmission in the South needs closer coordination between Afghanistan's and Pakistan's polio programs.
Limits: population and target figures rest on outdated community plans, some from 2017, made less certain by the returnees; caregivers' recall of doses may be inaccurate.
Sources
Based on Mone Hardy C, Rathee M, Chaudhury S, et al., "Progress Toward Poliomyelitis Eradication — Afghanistan, January 2023–September 2024," MMWR Morbidity and Mortality Weekly Report, volume 73, Centers for Disease Control and Prevention; a work of the United States government in the public domain. The report dates the authorities' reversal on house-to-house vaccination to both August and September 2024, so no month is given here.
Licence: CC0 1.0 (public domain) · Adapted from www.cdc.gov
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