The war on polio: Two out of three strains eliminated but hotspots persist

There have been 88 confirmed cases this year, including 72 in Pakistan, compared to just 28 at the same point last year. 

Nevertheless, a third war ravaged state – Nigeria – is now polio free after three years without new cases, and experts believe it only a matter of time and resource before Afghanistan and Pakistan wipe it out too.

“The eradication of type three shows we’re making progress,” Dr Zaffran said. “Even though we are not as close as we hoped we shouldn’t lose faith.”

A childhood scourge 

In the early 20th century polio – which remains incurable and preventable only through vaccination – was one of the world’s most feared illnesses. Endemic in 125 countries, polio caused the paralysis of more than 350,000 children a year. 

One of those children was Andy Gilliland, 64, who contracted the debilitating disease in Liverpool in 1959, when he was just four years old. 

“I remember waking up and being unable to walk and crying for my mum to come and help me,” he told The Telegraph. “I was in isolation in a hospital in Aintree for six months, in these glass cubicles where my mum couldn’t come in. She’d just wave through the window.” 

Polio left Mr Gilliland’s left leg paralysed and he still wears a full length caliber to help him walk, which made him the target of name calling and stigma as a child.

“We were treated quite poorly by the local community when I first contracted polio, because obviously it’s so virulent, so contagious. We were kind of treated a bit like lepers,” he said. 

Mr Gilliliand, who works with Rotary International’s End Polio Now campaign, has since visited India to meet polio victims there.

“When I was in hospital there were people with iron lungs, and so I always regarded myself as being let off relatively lightly. But India, it was very humbling. 

“I realised just how lucky I was. I saw at least 100 people with polio, but there was only one person with a caliber.

 “The world cannot get complacent about polio, we really can’t,” Mr Gilliland said – adding that all four of his granddaughters have had the polio vaccinations because “I won’t rest on my laurels”.

“It’s so virulent and dangerous and easy to spread, we have to eradicate it,” he said. 

The drive to wipe out polio

Polio is spread through contaminated sewage and the advent of sanitation in developed countries, alongside the development of an effective vaccine in the 1950s, saw a rapid reduction in new infections.

Experts believed that prospects for wiping out polio were good and in 1988 the Global Polio Eradication Initiative was established, with the aim of eliminating the illness by 2000. 

Although this target was missed, India – a country many people believed would never get rid of the disease – was officially declared polio free in 2014. 

Many thought it was only a matter of years before the illness became the second human disease – after smallpox – to be wiped from the face of the earth. 

But what experts had not bargained for was how events would knock the campaign off course. 

In Afghanistan and Nigeria, the Taliban and Boko Haram respectively barred vaccinators from areas they held. 

And in Pakistan, countless polio vaccinators have been attacked and killed by religious and political zealots. Matters there were not helped by CIA's use of a fake hepatitis B vaccination campaign to gather DNA samples in the hunt for Osama Bin Laden.  

Another problem has been persuading communities, who rarely see cases of polio and have more pressing concerns such as a lack of running water and electricity, of the importance of vaccinations. 

Earlier this year it emerged that parents were duping the health authorities in Pakistan, claiming their children had been vaccinated when they had not. 

The rise of rare vaccine-derived cases

Another unexpected turn in the fight against polio have been cases caused by the very thing that is meant to eradicate it: the vaccine itself. 

When a child is vaccinated the vaccine-virus replicates in the gut, generating an immune response. The vaccine is then excreted and very rarely can mutate and spread to other children, especially where vaccination coverage is low. This can then result in outbreaks of polio.

Vaccine-derived polio outbreaks have taken place in 12 countries in Africa and a handful in Asia so far this year – including the Philippines, where an outbreak was declared in September, almost 20 years after the country eradicated the disease. 

In 2016 the Global Polio Eradication Initiative switched from a vaccine containing three serotypes to one containing two serotypes in a bid to combat the spread of vaccine-derived viruses. 

A recent study, led by researchers at Imperial College, London, found that the “switch”, as it became known, was a success. But while some outbreaks were expected their number and magnitude have been harder to bring to a close than anticipated.

And the switch to the new vaccine means that some children have not been immunised against one of the polio types. 

So far this year there have been 95 cases of the vaccine-derived virus, the same number as at the same point last year. The outbreaks have occurred mainly in Africa where vaccination coverage is poor.

The response to these outbreaks has been to conduct mass vaccination campaigns. And next year, a new vaccine which is less susceptible to causing mutations, will be launched.

“I think the key thing that people have to recognise is that immunisation must continue,” Alok Sharma, International Development Secretary, told The Telegraph. “It’s not a question of, having eradicated polio across large parts of the world, we stop vaccination [campaigns].

“The UK is committed to the fight against polio,” he added. “If [the world] were to stop the work that is going on in the fight against polio, within a decade we would have around 200,000 cases a year. Which would be a huge step backwards.”

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