Pakistan's Polio Endgame: Why the Final Mile Remains Elusive

Four-year-old Shahmeer lived in Sujawal, a district in Sindh province, and his vaccination card was meticulously maintained. Every box was checked: pneumonia, diarrhea, measles, typhoid, polio. On March 5, 2026, he became Pakistan's first reported polio case of the year. He showed no paralysis, no joint pain, no visible distress. He went out to play as children do. What made his case remarkable was not what it revealed but what it concealed—he had contracted non-paralytic polio, a form of the disease that moves through a community almost invisibly, spreading the virus while leaving no obvious mark on its host.

Genetic analysis linked the virus in Shahmeer's body to environmental samples from Hyderabad, suggesting ongoing transmission in the province. His case crystallized Pakistan's central paradox: the country stands closer to eradication than ever before, yet the virus persists. It has simply become harder to see.

Pakistan has reached what health officials call "the last mile" three times in the past decade. In 2017, eight cases were reported. In 2021, only one. In 2023, six cases emerged. Each time, progress stalled. By the end of 2025, the count had climbed to 31. Three months into 2026, three more cases had appeared—from Sujawal, Bannu, and North Waziristan. The pattern repeats: near-elimination, then resurgence. Ayesha Raza Farooq, the prime minister's focal person on polio, acknowledges the challenge plainly. To be declared polio-free, Pakistan must record zero cases for three consecutive years, with no virus detected in humans, the environment, or laboratory samples. That threshold remains distant.

The arithmetic of the last mile is deceptively simple. Pakistan aims to vaccinate 45 million children in each campaign but consistently reaches only 43 million. Two million children slip through. During the February campaign of 2026, 950,000 children were not vaccinated. In April, 300,000 were missed. Behind these numbers are closed doors, absent children, and parents who turn away health workers. In Sindhi Para, a neighborhood in Karachi's Dalmia district, Samina and her team—Bilqis and Parmeela—move through narrow alleys each morning, vaccine carriers strapped to their bodies, ice packs keeping doses between two and eight degrees Celsius. They knock on doors, mark fingers with pen, chalk cryptic symbols at gates. They chat over tea, switch between Urdu and Sindhi, build relationships that make vaccination easier. Yet this familiarity coexists with deep suspicion. A woman once spat on Parmeela and screamed that she was poisoning children. A man pulled a gun on Samina repeatedly. In some homes, fathers forbid vaccination while mothers sneak children out when the men are away, asking workers not to mark the child's finger, only to note the tally on official sheets. The rumors driving refusal are persistent: the vaccine causes infertility, it is un-Islamic, it targets specific ethnic groups for population reduction.

Ninety-eight percent of all refusals in Pakistan come from 30 districts, many with histories of high polio incidence—Karachi, Peshawar, Quetta, and southern Khyber Pakhtunkhwa. During the first 2026 campaign, Karachi alone accounted for 58 percent of refusals. Azeem Khawaja, team lead for UNICEF Sindh, frames the problem as systemic. "Instead of strengthening the health system, we have invested in outreach, on which 70 percent of immunization coverage is dependent," he explains. When the government brings vaccines to every door, it creates an expectation that all health services will arrive the same way. When that does not happen—when water does not flow from taps, when children die from diseases other than polio, when roads remain broken—trust erodes. Some families use vaccination as a bargaining chip, demanding soap or paracetamol or road repairs before allowing their children to be vaccinated. "We are stuck in a vicious cycle that needs to be broken," Khawaja says.

The frontline workers who navigate this cycle are paid Rs12,000 for eight days of work in Karachi—barely enough to cover transport, let alone household expenses. Samina walks most of the distance to her assigned area despite living only ten minutes away by car. Her husband lost his job during the pandemic, and she is the sole earner for her family. Parmeela supports her mother and her dead brother's son on the same wage. In Bannu, payments have dropped to Rs8,200 for four to five days of work. In Quetta, a health worker who once earned Rs32,000 now receives Rs12,000, often weeks after campaigns end. Ayesha, a polio worker in Punjab, contracted polio herself at age two. She was bedridden for months, fitted with a prosthetic shoe, and later struggled to find a marriage proposal. She has a daughter now, and she walks door to door despite pain and stiffness in winter, despite falls, despite the absence of medical facilities for workers with disabilities. "I have polio, but I will not let anyone else go through the same pain," she says. For over a decade, she has been part of the very campaigns that could have prevented her condition. Yet the programme has cut her pay in the name of optimization.

Beyond refusals and low wages lies a deeper structural failure: routine immunization remains uneven across Pakistan. Each month, new children are born and enter the population. When routine vaccination coverage is inconsistent, pockets of under-immunized children accumulate. These are the "zero-dose" children—those who have never received even a single vaccine dose, neither through routine services nor supplementary campaigns. They are the ones missed because they were not home, because their parents refused, because they live in settlements beyond the state's regular reach. When such children contract polio, it is not surprising. It is expected. "These are the children the virus finds," says Professor Fatima Mir of Aga Khan University, "because they are completely unprotected." The gaps are not random. They concentrate in urban slums like the Al-Rashid Nomad settlement, in mobile and migrant populations, in underserved rural districts, and in areas shaped by insecurity. In these regions, even small lapses in coverage sustain transmission.

Environmental surveillance reveals the virus's persistence. Positive sewage samples from Karachi indicate that someone—a child or adult—is still excreting the virus into the system. The virus enters children's guts when they play near open sewers, come home without washing their hands, and eat contaminated food. It can take months before a paralytic case appears. Non-paralytic infections, like Shahmeer's, may never show symptoms at all. "Low case numbers do not necessarily signal safety," Professor Mir explains. "They may instead reflect immunity levels that prevent visible disease, while transmission continues." This is not a scientific failure. It is a failure of immunization systems and trust.

Pakistan and Afghanistan coordinate their eradication efforts, treating the two countries as a single epidemiological unit. The virus does not recognize borders, and neither can the response. Families live on both sides of the Durand Line. Tribes span across borders. People cross frequently for economic and social reasons. In 2025 alone, Pakistan conducted three national campaigns in coordination with Afghanistan. Surveillance data is shared. Every detected virus undergoes genetic sequencing to trace its origin. Transit vaccination has been expanded at bus terminals, highways, railway stations, and border crossings, reaching more than 14 million children in 2025. Yet the limitations are clear. Transit vaccination cannot replace door-to-door campaigns. Not every vehicle stops. Movement is continuous; vaccination is periodic.

Pakistan stands once again at a familiar threshold. The geography of transmission has narrowed but not disappeared. Most 2025 cases concentrated in southern Khyber Pakhtunkhwa, particularly in districts bordering Afghanistan. Karachi remains a key reservoir, shaped by high population density, migration, and persistent refusals. Under what officials call the "Roadmap to Zero," Pakistan aims to eliminate both human cases and environmental circulation. But eradication requires more than a single year of success. It requires relentless effort, consistency, and trust—the very things that have proven hardest to sustain. As Ayesha Raza Farooq reflects, "You may succeed once, but eradication requires repetition, trust, and consistency." The final two million children remain the hardest to reach. Until they are vaccinated, and until routine immunization strengthens across the country, the virus will continue to find the gaps.