Defying appeals from scores of nations, the White House said Thursday that President Clinton has decided to retain America's stock of the deadly smallpox virus.
Mr. Clinton concluded that the virus samples must be maintained to develop new drugs and vaccines to treat or prevent the disease, which was eradicated around the world in 1980 through an inoculation effort.
The United States and Russia are the only two nations with known smallpox stocks, but the administration fears it could have fallen into other hands, raising the threat of bio-terrorism. Smallpox is highly contagious and kills about 20 percent of those afflicted.
"No one else is supposed to have it," a senior administration official said. "We don't know who else might have it. But the virus stores very easily in freezers so it could be elsewhere. We don't know what has happened in the last 20 years ... who might still have the virus and may not be telling anyone that they have it."
"It could reemerge as a terrorist threat," said the official, who insisted on anonymity. "It could reemerge as an accident from a laboratory that doesn't know it has it. It could start spreading very quickly from that."
The World Health Organization recommended in 1996 that the U.S. and Russian laboratory caches be destroyed in June. The United States and scores of other nations agreed that the stocks should be destroyed. But President Clinton ordered that the decision be reviewed.
"Four years ago when this was last considered, the threat of bio-terrorism was not nearly as defined," the administration official said.
Announcing Mr. Clinton's decision, National Security Council spokesman Mike Hammer said, "The president has decided to seek a delay in the destruction of declared smallpox stocks." Russia also is opposed to their destruction.
Bio-terrorism experts have said in recent months that they believe the virus has been distributed to spots in Russia beyond the known laboratories, perhaps in places with less effective security controls.
That information originates with a former high Soviet research official, Ken Alibek, who defected to the United States in 1992 and testified before Congress last May. Others have verified Alibek's information, according to smallpox experts who spoke at a recent bio-terrorism conference sponsored by Johns Hopkins University.
A study released last month by experts at the National Academy of Science's Institute of Medicine recommended that the surviving laboratory specimens of smallpox be kept alive as a safety net in case the disease reemerges.
The study warned that with much of the world's population no longer protected by inoculation against smallpox, the virus could pose a serious threat. Most Americans below 30 have never had the inoculation, and remaining smallpox vaccination stocks could treat only about 6 million people. Even those supplies are deteriorating.
"The most compelling need fr long-term retention ... would be the development of anti-viral agents or novel vaccines to protect against a re-emergence ... due to accident or intentional release," the study said.
Reported By Terence Hunt