Last Updated

05 Dec 2002

Source: San Francisco Chronicle, April 8, 2002.

Taking stock of smallpox viruses

Public health experts divided on whether to save supply

Keay Davidson, Chronicle Science Writer

The "atomic bomb" of bioterrorism is the smallpox virus, which, if unleashed into a general population, might kill millions around the world in a few years.

Such a possibility, made more real by last fall's anthrax attacks that killed five people on the East Coast, has revived an old debate among public health experts:

Should the United States destroy its last remaining supply of smallpox viruses to prevent its possible theft by terrorists? Or should it hang onto them as sources of medical information that might save innumerable lives during a bioterrorist attack?

In recent weeks, that question has divided the deans of U.S. public health schools.

In a private petition started by Dr. Alfred Sommer, dean of the Bloomberg School of Public Health at Johns Hopkins University, two-thirds of his fellow deans have supported destruction of the remaining viruses. But a prestigious minority -- including the deans of public health schools at the University of California at Berkeley and Harvard University -- oppose destruction.

Sommer's two-page petition calls for "drastically reducing" -- in effect, destroying -- all smallpox stocks, including those of the United States.

"We strongly believe that the best defense against one particularly dangerous, potential terrorist agent, smallpox, is a global campaign to eradicate the virus from the face of the Earth," the petition states.

"The world united in a global campaign that eliminated all clinical smallpox over 20 years ago. The only reason this remains a potential threat is that samples of the virus have been retained, temporarily, for possible research purposes."

MILLIONS COULD DIE IN ATTACK

There's plenty at stake, both sides agree.

A simulation of a scientific and governmental response to a smallpox outbreak was conducted in June by Johns Hopkins researchers and other officials at Andrews Air Force Base. The simulation, dubbed "Dark Winter," assumed that terrorists deliberately infected people in Oklahoma City.

Within three months, the simulation showed, smallpox would kill a million people in 25 states. And that would be only the beginning of the scourge. Soon it might girdle the globe, threatening people in nations that in many cases have less sophisticated health care systems than America's.

Whether to destroy surviving smallpox viruses is a familiar issue. During the Cold War, the United States and Soviet Union cultivated these viruses for possible use in a global conflict, as supplements to their other technologies of mass destruction including nuclear and chemical weapons.

In the early 1970s, the United States and the Soviet Union signed an international treaty agreeing to stop developing biological weapons. Only "defensive" biological warfare research was still permitted -- for example, the study of deadly viruses to figure out ways to develop vaccines against them.

In the late 1970s, smallpox was declared eradicated from the human population. At that time, the World Health Organization arranged for the United States, Soviet Union, Japan and Great Britain to store surviving viruses for medical research purposes.

Now only two labs remain in business, in the United States and Russia.

OFFICIALLY STORED IN U.S., RUSSIA

The surviving U.S. viruses are stored in secure freezers at the Centers for Disease Control and Prevention, in a suburban Atlanta lab run by Dr. James Hughes, the CDC chief of infectious diseases. The Russians say their last smallpox viruses are stored at a lab in Novosibirsk operated by Dr. Lev Sandakhchiev.

"Officially, the virus is kept under secure conditions in only two countries, Russia and the U.S.," Sommer's petition notes. "Unofficially, concerns exist that the virus may be hidden by countries like Iraq, Iran and North Korea," although U.N. inspectors in Iraq never found evidence to support that contention.

WHO officials had planned to decide by 2002 whether to recommend completing the destruction of all remaining stocks of the virus. But in January of this year, amid post-Sept. 11 tensions, WHO called for delaying the destruction to give scientists time to develop new vaccines and drugs to treat smallpox.

Last month, federal and corporate health officials issued the surprising announcement that enough smallpox vaccine will be available to inoculate most Americans against the smallpox threat much sooner than expected. That announcement has helped to revive the debate over eradicating supplies of the virus.

Sommer acknowledges that it might never be known whether every vial of virus has been destroyed, but he insists that a global eradication campaign will eliminate the vast majority of such stocks and greatly reduce the risk that terrorists will obtain them.

"You never can get perfect safety on these things. My concern is that if we experiment with (smallpox virus), then a whole bunch of other countries will experiment on it," Sommer explained in an interview with The Chronicle.

"And then someone will bioengineer a form of the smallpox virus that will be resistant to whatever drugs we make and whatever vaccine we might make," he warned.

NORTH-SOUTH DIVIDE IN CALIFORNIA

California experts are split on the petition. The petition signers include Linda Rosenstock, dean of the University of California at Los Angeles School of Public Health. But her Northern California counterpart, dean Dr. Edward Penhoet of UC Berkeley's School of Public Health, declined to sign.

"I think the value of these stocks as a potential research tool could be significant," Penhoet said in a phone interview. "There are so many things we don't know about the pathogenesis of smallpox, about the function of genes on the (smallpox) virus."

Opponents argue that the surviving smallpox viruses might be needed for future medical research after a smallpox attack. They point out that no one is sure whether Iraq, North Korea or other unfriendly nations have secret stashes of smallpox virus.

The petition was rejected by Dr. Barry Bloom, dean of the Harvard School of Public Health.

"In the long run, I would be very happy to support the destruction of known (smallpox) stocks. But I don't feel that would be the most prudent course at this time," Bloom said in an interview.

Improved understanding could prove especially important should anyone bioengineer a more lethal form of smallpox virus, Bloom said. "There's a need for a better understanding of how the virus causes the disease . . . so we (can) make even better vaccines."