Scientists Debate the Destruction of Remaining Vials of Smallpox Virus : Health: Hundreds of test tubes sit in labs in Atlanta and Moscow. Some researchers want history’s deadliest disease kept alive for study; others want it extinct.

They look harmless enough--hundreds of little test tubes sitting in a freezer. But the freezer is padlocked, the laboratory guarded. The workers inside wear protective suits.

These vials hold all that remains of smallpox. A turn of a switch would kill the virus, ensuring the world would never again be ravaged by history’s deadliest disease.

The smallpox vials have prompted a fierce moral debate: Should scientists deliberately destroy an entire species, one that possibly could teach them how to fight other diseases?

“Some people forgot just how terrible this disease was,” said Dr. Brian Mahy of the Centers for Disease Control and Prevention. “If we had a similar control of all the HIV in the world, I don’t think there would be any question about destroying it.”

Smallpox killed millions of people over thousands of years, from ancient Egypt to 20th Century America. Some doctors said it was more deadly than all other infectious diseases combined.

The disease caused convulsions, internal bleeding and painful lesions filled with pus. One in four victims died. Survivors were deeply scarred and sometimes blinded.

A vaccine was discovered in the 1790s. Almost 200 years of immunizations later, in 1977 smallpox became the only disease ever eradicated.

Meanwhile, the virus that causes smallpox was kept for study in two places: the CDC in Atlanta and Russia’s Institute for Viral Preparations in Moscow.

Russian scientists were supposed to map smallpox genetically--to see how it works and what diseases it’s related to--and then destroy it. They have mapped two strains, and the CDC is working on a third.

But those maps haven’t revealed all that doctors need to know, so the CDC is reconsidering killing the virus. It will consult the world’s top virologists at a meeting in Scotland in August and may decide by the end of the year.

“Destroying all these vials now will compromise any possibilities of finding out more information,” said Dr. Bernard Moss, chief of virology at the National Institutes of Health, who wants the virus preserved.

What if smallpox holds clues about other diseases? What if it is similar to a new disease waiting to emerge?

“There’s a lot we would like to know,” agreed Mahy, the CDC’s top virologist. “We don’t know how it kills people.”

The World Health Organization wants smallpox destroyed to ensure that it won’t ever threaten a now-defenseless world.

Vaccination has ceased except in the Russian, Canadian, Israeli and U.S. armies, which fear biological warfare. The last smallpox death was from a lab accident in 1978 in England, before the CDC and Russia appropriated the world’s remaining virus.

At the CDC, 400 tiny vials of separate smallpox strains are frozen in liquid nitrogen and guarded in a laboratory that the Defense Department helped design. Workers must be vaccinated and don full-body pressurized “space suits” to enter, and take a chemical shower to leave.

In Moscow, not far from the Kremlin, 200 smallpox vials are kept in a special freezer, guarded by a regiment of ex-army officers. Despite the political instability in the country, the vials are “quite safe,” said Dr. Vladimir Loparev, a Russian scientist visiting the CDC.

A flip of a switch would warm the nitrogen and kill the smallpox.

Scientists could still study it even if they killed it, said Dr. Kenneth Berns of the American Society of Microbiology. The CDC grew smallpox, separated its genes, rendered them impotent and cloned them.

And if it ever somehow re-emerged naturally, the vaccine is made from a very common virus, Berns said.

But the clones may not act the same as live smallpox, Mahy said.

“Smallpox information could add to our understanding of viruses and how they cause disease and how they attack humans,” he said. “I don’t think we should throw away something until we’ve fully exploited it.”

Others said it’s just time to close the books on an old disease.

“We can be secure that in upriver Amazon, the mountains of Ethiopia, the dense jungles of Indonesia, the teeming population of India, this disease no longer exists,” said Dr. William Schaffner of Vanderbilt University School of Medicine.

Eradication “was the awesome achievement. . . . This puts the final period to the sentence.”