Eradication Within Reach — Why Pakistan Is Close, and What Could Still Go Wrong

"Eradication within reach" is a phrase the Pakistan programme has earned and also had to defend. In 2021 the country recorded a single wild poliovirus case for the whole year. That is as close to zero as any endemic country has come without crossing the line. It is also a reminder of how the last mile behaves: 2022 ended with 20 cases, 2024 with 74.

What the record actually shows

Two things are true at once. The long-run trend is one of the most successful public health efforts in Pakistan's history — from roughly 20,000 cases a year in the early 1990s to 31 in 2025. And the short-run record is volatile, because when transmission is reduced to a few chains, any interruption in campaign quality lets those chains expand again.

The full year-by-year series is on the province-wise cases page; the current year's detail is tracked on the district-wise tracker.

Why zero is harder than 99 per cent

Polio is mostly invisible. Around one infection in two hundred causes the paralysis that gets reported, so a single confirmed case implies that hundreds of children were infected in the same community. The programme therefore cannot judge success by case counts alone — it relies on environmental surveillance, sampling sewage at more than a hundred sites nationwide, to see the virus before it paralyses anyone.

That is also why a quiet year is not proof of interruption. Certification requires three consecutive years with no wild poliovirus detected in people or in the environment, with surveillance good enough to be believed.

The four things that decide the outcome

• Access. Campaigns only work where teams can actually go. Security-related access constraints in southern Khyber Pakhtunkhwa, particularly around Bannu and North Waziristan, have repeatedly left children unvaccinated across consecutive rounds — and that is where most recent cases have come from.
• Campaign quality. Reaching a house is not the same as vaccinating the child in it. Missed children, absent families, and teams marking houses as covered without finishing the job are the failure modes the programme monitors most closely.
• Community trust. Refusals are a smaller share of missed children than access problems, but they concentrate in exactly the communities where transmission persists. The work of religious scholars in answering vaccine misconceptions has been central to reducing them.
• Routine immunisation. Campaigns are a supplement, not a substitute. Children who complete the routine EPI schedule are protected in a way that repeated door-to-door rounds alone cannot guarantee.

What would confirm it

Interruption will not be announced on the day the last case occurs — it can only be recognised afterwards, once surveillance has stayed silent long enough to trust. The practical signals to watch are the number of environmental samples testing positive, the geographic spread of those positives, and whether southern KP moves from persistent detection to sustained absence.

Pakistan has been close before. The difference between close and finished is whether every campaign round reaches the same hard-to-reach children, in the same districts, without a gap. See the eradication strategy for how the programme is trying to make that happen.