Microbe of the Month: Endangered, but not quite extinct: The virus that causes polio could go the same way as smallpox and be history by 2000, writes Bernard Dixon

THE WORLD Health Organisation has had to abandon its much-trumpeted goal of attaining 'health for all by the year 2000'. Poverty, military conflict, political and religious barriers and the emergence of diseases such as Aids have conspired to forestall such an achievement. But there is one WHO target that remains very much in sight. The virus responsible for poliomyelitis, which can cripple or kill its victims, could well be eliminated by the turn of the century.

At present, only one disease-causing microbe has been rendered extinct in nature - the smallpox virus, whose eradication the WHO announced in 1987 following a triumphant worldwide vaccination programme. The only surviving samples of the virus are held in secure laboratories in Atlanta and Moscow. Following discussions at the International Congress of Virology in Glasgow in August, the decision whether or not to destroy those stocks will be taken at the World Health Assembly in Geneva next May.

There are two principal grounds for believing that polio will follow smallpox into the textbooks of medical history. First, immunisation in both cases confers solid, long-lasting immunity. Even if the virulent virus is introduced into a vaccinated community, therefore, it cannot cause disease and has negligible chances of spreading or surviving. Second, poliovirus, like smallpox virus, does not infect or persist in any other living creature (as does the malarial parasite in mosquitoes).

Where immunisation has been widely deployed, it has already vanquished polio. In 1955, there were more than 76,000 cases of the disease in the United States, Canada, Australia, New Zealand, the Soviet Union and 23 European countries. By 1967 that figure had fallen to 1,013, and today polio is very rare in industrialised regions. These advances have come from two vaccines. The first, consisting of 'killed' poliovirus and given by injection, was developed by Jonas Salk and introduced in the late Fifties.

The second, a live but weakened virus taken by mouth, was devised by Albert Sabin and came into use in the early Sixties.

Today, each year, more than 80 per cent of the world's infants are immunised against polio. The problem for the WHO is covering the remaining 20 per cent, many of whom live in parts of the world that are

not easy to reach by mobile immunisation teams. Yet this was precisely the challenge that was faced and overcome in the crusade against smallpox.

But no battle is won until the enemy has been defeated. That is why public- health specialists have been warning that as long as even the smallest pockets of unvaccinated, or inadequately vaccinated individuals, exist, even the richest countries face the risk of sudden outbreaks. Dr David Carrington and colleagues at the Ruchill Hospital in Glasgow recently reported the results of a survey in which they showed that only a third of people tested in their city had adequate levels of antibodies against one of the three types of poliovirus. To ensure full protection, it is essential that everyone has received the full sequence of three doses of vaccine.

There is another problem, illustrated by the outbreak of poliomyelitis in the past year in the Netherlands, a country with one of the most efficient health services in Europe. As occurred in 1978-79, the epidemic arose in Protestant communities whose allegiance to the Dutch Reform Church leads them to refuse immunisation on religious grounds. Although the outbreak has been contained by offering immediate vaccination to school pupils and other people likely to have been in contact with members of the affected group, at least 68 people have had the disease, some suffering paralysis. The 1978-79 incident eventually affected 110 people, 80 of whom were paralysed. In neither case has the original source of the virus been pinpointed, although presumably it was imported from a part of the world where the disease is still endemic.

Ironically, religious leaders are one group the WHO has been urging to become involved in its global eradication efforts. The campaign has brought together disparate forces, from the cricketer Imran Khan, who has promoted immunisation in Pakistan, to Rotary International, which is raising funds towards the elimination of polio by 2005. Religious leaders would be a welcome addition to these forces.

A little subversion might help, too. There is a good chance that if the Netherlands had chosen the Sabin vaccine for its routine immunisation programme, at least some of the children now paralysed by polio would have escaped. This is because the living Sabin virus, unlike the killed Salk virus, is shed in the faeces of vaccinees. It is thus passed to other children, who become immunised without either their or their parents' knowledge.

Which prompts the question: should vaccine manufacturers, using the new techniques of genetic manipulation, now begin to design vaccines against other infections with just this aim in mind - the incidental vaccination of other children? Would that be common sense or an infringement of religious freedom?

(Photograph omitted)

Start your day with The Independent, sign up for daily news emails
Voices
There will be a chance to bid for a rare example of the SAS Diary, collated by a former member of the regiment in the aftermath of World War II but only published – in a limited run of just 5,000 – in 2011
charity appealTime is running out to secure your favourite lot as our auction closes at 2pm tomorrow
News
people
Arts and Entertainment
Caroline Flack became the tenth winner of Strictly Come Dancing
tvReview: 'Absolutely phenomenal' Xtra Factor presenter wins Strictly Come Dancing final
Life and Style
A still from the 1939 film version of Margaret Mitchell's 'Gone with the Wind'
life
PROMOTED VIDEO
Arts and Entertainment
J Jefferson Farjeon at home in 1953
booksBooksellers say readers are turning away from modern thrillers and back to golden age of crime writing
Sport
Amir Khan is engaged in a broader battle than attempting to win a fight with Floyd Mayweather
boxing Exclusive: Amir Khan reveals plans to travel to Pakistan
News
Stacey Dooley was the only woman to be nominated in last month’s Grierson awards
mediaClare Balding and Davina McCall among those overlooked for Grierson awards
Voices
Joseph Kynaston Reeves arguing with Russell Brand outside the RBS’s London offices on Friday
voicesDJ Taylor: The great tradition of St Paul and Zola reached its nadir with a worker's rant to Russell Brand
News
Twitchers see things differently, depending on their gender
scienceNew study shows that birdwatching men have a lot in common with their feathered friends...
News
i100
News
Xander van der Burgt, at the Royal Botanic Gardens, Kew
scienceA Kew Gardens botanist has found 25 new large tree species - and he's sure there are more out there
ebooks
ebooksA year of political gossip, levity and intrigue from the sharpest pen in Westminster
Latest stories from i100
Have you tried new the Independent Digital Edition apps?
Independent Dating
and  

By clicking 'Search' you
are agreeing to our
Terms of Use.

iJobs Job Widget
iJobs General

Austen Lloyd: Senior Private Client Solicitor

Excellent Salary: Austen Lloyd: SURREY - An outstanding high level opportunity...

Austen Lloyd: Construction Solicitor - London

Very Competitive Salary : Austen Lloyd: NICHE CITY FIRM - We are making a disc...

Austen Lloyd: Construction Solicitor - London

Very Competitive Salary : Austen Lloyd: NICHE CITY FIRM - We are making a disc...

Recruitment Genius: Finance Director

£65000 - £80000 per annum: Recruitment Genius: Finance Director required to jo...

Day In a Page

The week Hollywood got scared and had to grow up a bit

The week Hollywood got scared and had to grow up a bit

Sony suffered a chorus of disapproval after it withdrew 'The Interview', but it's not too late for it to take a stand, says Joan Smith
From Widow Twankey to Mother Goose, how do the men who play panto dames get themselves ready for the performance of a lifetime?

Panto dames: before and after

From Widow Twankey to Mother Goose, how do the men who play panto dames get themselves ready for the performance of a lifetime?
Thirties murder mystery novel is surprise runaway Christmas hit

Thirties murder mystery novel is surprise runaway Christmas hit

Booksellers say readers are turning away from dark modern thrillers and back to the golden age of crime writing
Anne-Marie Huby: 'Charities deserve the best,' says founder of JustGiving

Anne-Marie Huby: 'Charities deserve the best'

Ten million of us have used the JustGiving website to donate to good causes. Its co-founder says that being dynamic is as important as being kind
The botanist who hunts for giant trees at Kew Gardens

The man who hunts giants

A Kew Gardens botanist has found 25 new large tree species - and he's sure there are more out there
The 12 ways of Christmas: Spare a thought for those who will be working to keep others safe during the festive season

The 12 ways of Christmas

We speak to a dozen people who will be working to keep others safe, happy and healthy over the holidays
Birdwatching men have a lot in common with their feathered friends, new study shows

The male exhibits strange behaviour

A new study shows that birdwatching men have a lot in common with their feathered friends...
Diaries of Evelyn Waugh, Virginia Woolf and Noël Coward reveal how they coped with the December blues

Famous diaries: Christmas week in history

Noël Coward parties into the night, Alan Clark bemoans the cost of servants, Evelyn Waugh ponders his drinking…
From noble to narky, the fall of the open letter

From noble to narky, the fall of the open letter

The great tradition of St Paul and Zola reached its nadir with a hungry worker's rant to Russell Brand, says DJ Taylor
A Christmas ghost story by Alison Moore: A prodigal daughter has a breakthrough

A Christmas ghost story by Alison Moore

The story was published earlier this month in 'Poor Souls' Light: Seven Curious Tales'
Marian Keyes: The author on her pre-approved Christmas, true love's parking implications and living in the moment

Marian Keyes

The author on her pre-approved Christmas, true love's parking implications and living in the moment
Bill Granger recipes: Our chef creates an Italian-inspired fish feast for Christmas Eve

Bill Granger's Christmas Eve fish feast

Bill's Italian friends introduced him to the Roman Catholic custom of a lavish fish supper on Christmas Eve. Here, he gives the tradition his own spin…
Liverpool vs Arsenal: Brendan Rodgers is fighting for his reputation

Rodgers fights for his reputation

Liverpool manager tries to stay on his feet despite waves of criticism
Amir Khan: 'The Taliban can threaten me but I must speak out... innocent kids, killed over nothing. It’s sick in the mind'

Amir Khan attacks the Taliban

'They can threaten me but I must speak out... innocent kids, killed over nothing. It’s sick in the mind'
Michael Calvin: Sepp Blatter is my man of the year in sport. Bring on 2015, quick

Michael Calvin's Last Word

Sepp Blatter is my man of the year in sport. Bring on 2015, quick