The execution of one of the biggest killers in history, the smallpox virus, is being planned for the end of this year.
The virus' death sentence comes 13 years after the World Health Organization declared that it had eradicated smallpox, a disease that has killed, blinded and disfigured uncounted millions of people. The organization's global vaccination campaign broke the chain of transmission of the disease, which occurred only in humans.
But while the disease is gone, some of the virus remains. What are believed to be the last remaining stocks of the smallpox virus have been kept frozen in liquid nitrogen in two closely guarded laboratories in Atlanta and Moscow.
Armed with newly developed maps of the molecular structure of the virus, WHO, a United Nations agency based in Geneva, Switzerland, has called for simultaneous destruction of the remaining stocks by New Year's Eve.
With only 18 weeks until the planned destruction, a last-minute debate among scientists over whether the stocks should be destroyed could lead to a stay of execution.
The U.S. and Russian governments have the responsibility for destroying the virus stocks, probably by heating them to a very high temperature.
Even if the virus is destroyed, some stocks of the vaccine to protect against smallpox could be kept available. The vaccine is made from a virus different from the one that causes smallpox.
Wiping out smallpox was perhaps public health's greatest triumph. It is the only disease ever eradicated.
The health organization's committees have long held that destroying the smallpox virus is the logical final step in the eradication process, and at a meeting in 1990, they set Dec. 31, 1993, as the execution deadline.
Those who want to retain the smallpox virus must now make strong, convincing arguments to delay the execution or even reverse the policy, several health officials said.
"There's no question the virus will be destroyed," said Dr. Yuri Ghendon, a health organization official. "The question is, is this the correct time?"
The Centers for Disease Control and Prevention, the federal agency that holds the smallpox stocks at its headquarters in Atlanta, has said it plans to meet the New Year's Eve deadline. But Dr. Walter R. Dowdle, the centers' acting director, said, "It is fair to say we may have to delay it."
Destruction of the virus is intended to eliminate the risk that the virus could escape from a laboratory, infect large numbers of people and require emergency vaccination of millions more.
The U.S. and Russian governments also want to eliminate the costs of the elaborate security to guard the remaining stocks of smallpox virus from accidents and terrorists. And destruction of the virus would eliminate any chance of financially strapped researchers selling samples.
"Who can guarantee 100 percent that the virus cannot escape for some reason? And if it escapes and infects somebody, there could be an outbreak like there was in the 15th and 16th centuries," Dr. Ghendon said. He added that the threat was especially great because most people under 15 have not been vaccinated and immunity for older people had probably waned.
Yet if the virus is destroyed, scientists in the future will not be able to study it for whatever reason might arise.
"It is reckless and presumptuous to destroy the virus, because you cannot be sure that there won't be a need for it someday," said Dr. Donald R. Hopkins, a former official of the disease centers who is now a senior consultant to the Carter Center in Atlanta.
Officials of the American Society for Microbiology in Washington, the American Society for Virology in Milwaukee, and the American Type Culture Collection -- which kept the smallpox virus as one of its 55,000 biological specimens in Rockville, Md., before turning it over to the disease centers -- have supported the health organization's execution plans. As many health organization members and other scientists begin to hear about the plans, however, a small but growing number of them are questioning or opposing the decision.