Decision to be made in May on destruction of last samples
(IPS) LONDON -- For the past 15 years, Russian and American
scientists have kept under close guard 600 samples of a virus
associated with a disease that was once a scourge of mankind. But in May, those supplies of the variola virus locked away in special
freezers might receive a final death sentence; that's when when general assembly of the World Health
Organisation (WHO) will decide whether or not to accept a
recommendation from the WHO Executive Board on keeping the world's
remaining stocks of smallpox virus.
If the WHO assembly accepts the recommendation, the virus stocks will be destroyed on Jun. 30, 1999.
WHO recommends that 500,000 doses of smallpox vaccine should be kept as well as the vaccinia virus strain used to make it. These will be stored in the WHO Collaborating Center on Smallpox Vaccine at the National Institute of Public Health and Environmental Protection in Bilthoven, the Netherlands.
Cloned DNA fragments of variola virus genome -- which are not themselves infectious -- would also be kept as a resource for analysing variola virus genes and protein structure and function, and be kept at the U.S and Russian centers.
"This means there is no danger that we would not be able to diagnose the disease should it ever reappear," explains Dr David Heymann, head of WHO's Division of Emerging Viral and Bacterial Disease Surveillance and Control (EMC) in Geneva.
He adds that all the evidence suggests that it has been eliminated. Surveys have been carried out regularly over the past 15 years among those who have never been vaccinated to identify any scarring which could have come from contracting smallpox.
But no cases have been found. Tests for antibodies to the virus have also proved negative.
Smallpox has long been in the biological warfare arsenal
dates set for destruction of the virus have been
deferred because of a range of concerns on the part of scientists
and some health officials. Destruction was originally scheduled
for December 1993 and again for June last year but in the event
the WHO Executive Board could reach no consensus.
Those favouring destruction argue that if the virus were to escape it would cause havoc and death worldwide on a population now largely unvaccinated. However, some researchers object to deliberately destroying an entire species of virus which might be useful in the fight against other diseases.
"The only reason one might be concerned would be losing a biological species from the Earth deliberately," says Dr Brian Mahy of CDC. "To wipe out a species is always a concern."
Another factor in the delay was pressure from Defense ministries and other agencies in certain countries who sought to do more work on protective measures -- smallpox has long been in the biological warfare arsenal.
In 1994, for example the UK delegation was lobbying to delay the execution. According to Dr. Graham Pearson, head of the UK's Chemical and Biological Defense Establishment at Porton Down, there is a continuing risk that some states may have clandestine stocks of variola.
If they were to change the virus slightly so that the existing vaccine is ineffective, samples of the original live virus would be needed to develop rapid tests for smallpox virus attacks as well as new vaccines, he argues.
Provided the Assembly adopts the resolution in May, the smallpox will disappear from the earth in 1999 through destruction in an autoclave carried out under international supervision. The process will take two hours, according to guidelines developed by WHO.
The autoclaves will automatically heat up to 266 degrees Fahrenheit for 40 minutes and then repeat the process. The destruction will take place at the centres where the virus is held and will be watched by officials at both labs via satellite as well as being videotaped. Those present will be vaccinated and will wear protective clothing.
The debate about destruction will no doubt continue as May approaches.
"If there was an outbreak today, about a million people could die or go blind from the disease in the several months it would take to get enough vaccine produced," says Russian virologist Yuri Ghendon, scientific secretary of the expert committee to recommend destruction in 1994.
If researchers want to study the virus, they can use cloned variola DNA, he says. "Why anybody would want to study the virus of a disease that no longer exists when there are micro-organisms emerging or re-emerging that are real public health threats today beats me," he says.
Donald Henderson, who spearheaded WHO's 10-year campaign to eradicate smallpox and is now senior scientific adviser to the U.S Department of Health and Human Services, supports destruction. "There is no doubt that some information will be irrevocably lost by destroying the virus. But it's hypothetical how useful that would be."
Less than 30 years ago, smallpox was endemic in 31 countries
was officially declared eradicated in 1980. The last
case had been registered in Somalia three years earlier.
Vaccination was stopped.
Since then stocks of the variola virus have been reduced. Today only 600 known samples remain -- 400 of which are locked away at the Centers for Disease Control (CDC) in Atlanta, Georgia, and the remainder at Russia's State Research Centre for Firology and Biotechnology at Koltsovo in the Siberian region of Novosibirsk.
Smallpox killed up to 600,000 people a year in Europe from the 16th to the 18th century. It took nearly 200 years of immunisations to wipe out the disease after a vaccine was discovered in the 1790s.
Less than 30 years ago, smallpox was endemic in 31 countries. At that time, between 10 and 15 million people were stricken with the disease each year. Of these nearly two million died. Millions of survivors were disfigured. Others were blinded for life.
Smallpox was the first disease to be totally eradicated.
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