More than six decades on, it is hard to imagine the joy and relief that greeted news of the polio vaccine. In the US, church bells sounded, children were let out of school early and people embraced in the street at the prospect of vanquishing a virus that can cause paralysis, sometimes fatally.
The subsequent campaign against the virus has come remarkably close to eradicating it, in one of the great global health success stories. As recently as 30 years ago, 350,000 children a year were paralysed. Now, two of the three wild polio strains have been eradicated, and two years ago Africa was declared free of wild polio.
Yet authorities are now offering the vaccine or booster to all children aged one to nine in London, after polioviruses were found in sewage samples. Similar testing has found them in New York, and one man living just north of the city has become paralysed – the first case diagnosed in the US for almost a decade. Israel has identified its first cases since 1988. All of these seem to be connected. Most of those detected in London have been vaccine-like, but some samples have contained vaccine-derived poliovirus; the oral polio vaccine (no longer used in the UK) has safeguarded huge numbers of people, but very occasionally mutates and causes paralysis in poorly protected populations.
Vaccination rates in the UK and many other places are good. But geographical pockets of low coverage mean that outbreaks are a threat to a relatively small number of people. The very success of vaccination means that – without the terrifying sight of children in iron lungs – the danger has seemed largely remote and theoretical, rather than real and current. General vaccine hesitancy or opposition has also been a growing problem.
The risks are much greater in parts of the developing world. This spring, Pakistan confirmed its first case of polio for more than a year, and Mozambique confirmed its first wild (but imported) polio case in 30 years, after Malawi detected a similar strain in February. The pandemic disrupted immunisation programmes already challenged by war and other instability – compounding the relative lack of progress made over the last decade. The World Health Organization and Unicef, which hoped that 2021 would be a year of recovery, recently warned instead of the largest sustained decline in childhood vaccination programmes for about 30 years, with 6.7 million more missing their third dose of polio vaccine than in 2019. Twenty-five million children missed out on one or more doses of the vaccine against diphtheria, tetanus and pertussis, and first-dose measles coverage dropped to the lowest level since 2008. This comes as soaring food prices exacerbate rising rates of severe malnutrition, weakening children’s immunity. And Covid-19 disinformation has bolstered anti-vaccine narratives.
Assuring people that the polio vaccine is not only effective and safe but very well-established is important – as is reminding them that old foes as well as new can seriously threaten our health. So is facilitating immunisation: reminding busy parents when vaccines are available or due, and making them more easily accessible, perhaps by offering them at community centres or schools. Protecting the UK also depends on efforts elsewhere. Shamefully, Britain has slashed its funding for the global eradication campaign, which needs $4.6bn. Covid made familiar the axiom that no one is safe until everyone is safe. That applies to old but persistent threats too.