Are you protected against polio?

The case of a young adult paralysed by polio in New York is not simply unexpected. It’s shocking. The last time polio was diagnosed in New York State was in 1990. And yet the virus has now also been found in waste-water samples in Rockland County, Orange County and New York City. As surveillance continues, we will learn more, but what we know already is enough. We have circulating poliovirus that can cause paralysis in these communities. Polio is an imminent threat.

Unlike Covid-19, polio is not a novel disease. Once a source of terror in summer months, the virus seemed headed to the history books. Successful vaccination campaigns in the 1950s meant wild poliovirus was declared eliminated in the United States in 1979 and from the Americas in 1994.

Today, polio is endemic only in the political disarray of Afghanistan and Pakistan, although Malawi and Mozambique have reported cases in the past seven months. Wealthy countries with monitoring in place are on high alert. On August 10, the UK Health Security Agency, seeking to avert a human tragedy that has already happened here, announced it would offer a booster dose to children in London because a poliovirus has been found in waste-water.

In a conversation, my colleague and friend Jane Cardosa, a Malaysian virologist, calmly noted, “In our part of the world, one case of paralytic polio is an outbreak.” The case in New York State is no fluke, freak accident or government conspiracy. And it’s not surprising that we have had just one person develop paralysis. Many are unaware that about 70 per cent of people who contract polio have no symptoms. About 25 per cent of people infected experience symptoms that are mild or flu-like — headache, fatigue, fever, stiffness, muscle pain, nausea, a sore throat — all of which could be mistaken for many other illnesses. Fewer than 1 percent of infected individuals develop paralysis. Of those paralysed, 2 to 10 per cent die when their breathing muscles become immobilised. On this virus, we simply cannot play the odds.

The greatest danger is to adults and children who are unvaccinated. While you may assume that you and your children are up-to-date with polio immunizations, now is the time for all adults, including those who are pregnant, to ensure that this is true.

The answer is simple, although the solution is not so easy. Vaccination coverage is too low in too many places, and unvaccinated and under-vaccinated individuals are too often clustered together. Approximately 60 per cent of 2-year-olds in Rockland and Orange Counties have completed their initial three-dose regimen. Well over 90 per cent coverage is the goal, and immunizing young children on time is what we are after. Immunised people have a virtual wall against paralysis and may shed less virus if they get infected. Community spread is what drives the emergence of paralytic strains.

Up-to-date polio immunisations are a requirement for school-age children. But more vaccinations are needed, and sooner. The greatest hurdle is vaccine resistance, which has grown astronomically. True, many people have lost confidence in government, and public health departments have borne the brunt. Some believe they can protect themselves and their families by going against the advice of public health experts and flouting state-mandated immunisation programmes.

It is my fervent hope that one day, we will declare that, like smallpox, polio has been eradicated. Vanished as a source of human illness. Global eradication remains within reach. If we get there, it will be because of vaccines. Childhood immunisation will be the hero of the story.