Health Secretary Sajid Javid says he is 'not particularly concerned' about the first reported case of polio in this country for almost 40 years, but his complacency will not be shared by public health experts and the medical profession.

Polio is a deadly disease which can have a devastating impact on a significant minority of people who become infected. It can cause life-changing disabilities, paralysis and even death.

In the 1950s, when Britain was hit by repeated epidemics, 7,000 people a year were paralysed. That number fell dramatically once a vaccine became available from 1962. But that achievement just emphasises how vital it is today to ensure that successive generations of children in Britain continue to be vaccinated.

The big concern is that, following the Covid pandemic, take-up rates for the polio jab have fallen, partly because the energies of the NHS have been focused elsewhere, partly because of distrust in certain ethnic minority communities, and partly because of the disinformation campaign against vaccines led by deluded conspiracy cranks and right-on middle-class households.

The statistics highlight a worrying trend. Although 95 per cent of UK children have had the correct number of polio doses by the age of two, that figure falls to 90 per cent in London, the incubator of the new outbreak. 

Even worse, when it comes to the pre-school booster, just 71 per cent have had it by the age of five in London. Moreover, less than half of all teenagers in eight local authority areas in England – mainly in the capital – have been vaccinated against polio.

In the west London borough of Hillingdon, the proportion of 13 and 14-year-olds who have been given this protection is just 35 per cent, and the picture is not much better further north in Middlesbrough, where 45.6 per cent of this group have been vaccinated. 

The use of vaccines is even more important today, given that we live in an increasingly open, diverse society. 

Large numbers of visitors and migrants arrive from the two countries where polio is still endemic – Pakistan and Afghanistan. Indeed, it is likely the outbreak in London will be traced to a traveller from one of those countries.

Vaccines are the crucial barrier against this scourge, yet some of the very groups that are the most vulnerable have the lowest take-up rates. That can be down to language difficulties, isolation, even religion.

But anti-vaxx zealots can be found right across society and, since the advent of Covid, they have been able to exert a disturbing influence, helped by social media.

The anti-Establishment warriors are often joined by affluent metropolitan liberals and so-called 'yummy mummies' whose attachment to organic lifestyles leads them to oppose the idea of putting anything 'unnatural' in their children's bodies. 

They think they are sophisticated but their belief system is dangerous, not just to their families but to the wider public.

With Covid so front of mind, the NHS has – understandably – given low priority to other vaccine campaigns. 

Only 85.5 per cent of children have had two doses of the MMR vaccine by the age of five, even though the World Health Organisation says that 95 per cent of children need to be vaccinated.

And, like polio, tuberculosis has made an unwelcome return to Britain. Vigilance is always necessary when diseases have not been fully conquered across the world.