Polio: is the old scourge returning?
Gordon Richardson was only three when he was paralysed by polio. “At first I could only use my right eyelid,” he told Eleanor Hayward in The Times. “Gradually the feeling returned to my head, shoulders and arms.” But his legs “never worked again”, and he has no memory of being able to walk. At his boarding school in Yorkshire, he’d drag himself upstairs to his dormitory using only his arms.“I was the first pupil in a wheelchair to attend the school. Sometimes the other boys would help by picking me up and carrying me around. But mostly I just got on with life.” Richardson had caught the disease in 1956, towards the end of a wave of epidemics that swept western Europe in the 20th century. At its peak in the mid-1940s, polio caused paralysis in 7,000 people, largely children, each year in Britain; many were kept alive using iron lungs. It spread mostly via contaminated water in cities. So last week’s news that the polio virus had been detected in sewage from north and east London has understandably caused concern.
“Covid-19 variants, monkeypox and now polio: you might wonder what else will be thrown at us in 2022,” said Devi Sridhar in The Guardian. But though polio’s return must be taken seriously, there’s no need to panic. No one has come forward suffering from its symptoms (most cases are asymptomatic). We only know about the virus’s presence because of Britain’s effective system of waste-water analysis. And this disease should be easy enough to control. We have a vaccine which is 99-100% effective, and about 85% of Britons have had it; this will prevent it from spreading.
There are two types of polio, said Tom Chivers in The i Paper. There’s the “wild” type, which has been eradicated in all but a few areas such as the borders of Afghanistan and Pakistan. The kind found in London’s waste water is the second form, a “vaccine-derived poliovirus”. This comes from the type of vaccine that uses a live, but weakened virus, which is administered orally on a pill or sugar lump. Sometimes the weakened strain is able to reproduce itself in vaccinated people, and to spread to others; it can become as dangerous as the wild type. The oral vaccine has not been used in Britain since 2004; we now use an injected, deactivated virus instead. But the oral vaccine is still used in many parts of the world, because it’s cheap and easy to administer. “The likeliest explanation” for the polio in our waste water is that it came from someone who was given the vaccine as a child abroad. This discovery is a salutary reminder that “polio is still out there – it is damaged but not defeated”.