London plans polio booster drive for nearly one million children after virus found in sewage

Health officials are preparing catch-up jabs for children under nine after repeated poliovirus detections in London wastewater renewed fears of silent transmission.

Health officials in London are preparing a large catch-up vaccination drive after poliovirus was repeatedly detected in the city’s sewage, prompting concern that a disease once eliminated in the United Kingdom could still find pockets of vulnerability. According to the World Health Organisation, poliovirus has been found in London wastewater on multiple occasions since February, and the plan is to offer booster doses to nearly one million children under the age of nine, including many who have already been vaccinated.

The move reflects a wider warning from the WHO that no country is completely safe until polio is eradicated everywhere. The agency has said that countries which had previously been free of the disease have seen it return through imported virus, underlining how easily global travel can carry infections across borders. Although Britain was declared free of polio in 2003, the latest sewage findings have revived public health concerns and prompted authorities to act quickly to reduce the risk of spread.

Polio remains a dangerous viral disease that primarily affects young children. The WHO says it can cause anything from mild illness to severe paralysis, and in some cases death. Most infections cause no symptoms at all, which makes silent transmission especially difficult to detect. When symptoms do appear, they can include fever, headache, nausea, muscle pain and stiffness. In the most serious cases, the virus attacks the nervous system, leading to permanent weakness, paralysis of the limbs or failure of the muscles used for breathing and swallowing.

The global eradication campaign has made major progress over the past three decades. Since the launch of the Global Polio Eradication Initiative in 1988, cases have fallen by about 99%, according to WHO data. The agency says the second type of wild poliovirus has been eliminated worldwide, leaving only type 1 still circulating. WHO also confirmed in August 2020 that Africa had been certified free of wild poliovirus, a milestone credited to governments, health workers and local communities that helped protect millions of children.

Even so, the disease has not disappeared. The WHO’s latest immunisation data show that gaps in routine childhood vaccination remain significant, with millions of infants still missing at least one recommended dose of vaccine each year. The agency has warned that conflict, disrupted supply, poor access and misinformation continue to leave children exposed. In its most recent results report, WHO said reported wild polio cases fell sharply in 2025, but stressed that fragile and high-risk settings remain a major obstacle to final eradication. Health experts say the London booster campaign is a reminder that polio can still re-emerge wherever immunity weakens, even in countries that long ago thought the threat had passed.