Unnatural Causes: Biological Weapons and Bioterrorism

UC Davis microbiologist Mark Wheelis, an infectious disease and biological weapons expert who is frequently consulted by the news media, shares his thoughts on the threat of biological warfare.

By Debra C. Cleveland

Wheelis is a member of the Federation of American Scientists and chairs its Biological Weapons and Toxins Verification Program's (BTW) Subgroup on Investigations. Among other activities, the BTW program explores ways to prevent further proliferation of biotechnology for military applications.

In 1980, the World Health Organization announced that the smallpox virus had been eradicated. The world's only known stores of the smallpox virus, variola, remain in high-security laboratories at the Centers for Disease Control and Prevention in Atlanta, Ga., and at Vector in Novosibirsk Region, Russia.

Both of these smallpox stores were to be destroyed in June 1999, theoretically eliminating the fearful virus forever. Despite protests from scientists and health care agencies who claim the virus is too dangerous to keep, President Clinton decided to preserve the United States' store.

Mark Wheelis agrees with Clinton's decision--not too long ago, he wouldn't have.

Wheelis, a senior lecturer in microbiology, says that until six months ago he was a proponent of destroying the smallpox stores. "I strongly supported destruction because the virus has inflicted enormous suffering on humanity. No cure exists and no storage facility is absolutely secure. In addition, scientists have sequenced the genomes of several strains of the virus." However, Wheelis changed his mind after recent disclosures that the Soviet Union had an extensive, covert biological weapons program, which included manufacturing variola, and may have passed the virus to North Korea.

Electron microscopic image of smallpox virus

"If North Korea has a smallpox stock, then the United States needs its smallpox stores to develop both a new vaccine, because the classic vaccine is not entirely satisfactory, and an anti-viral drug. The latter needs to be tested directly on the smallpox virus rather than on something closely related in the hope that smallpox would respond the same way," says Wheelis.

Smallpox would be a sinister biological weapon: virtually everyone is susceptible, worldwide vaccination having stopped 20 or more years ago, and it has a 30 percent mortality rate. But other organisms are likely biological warfare agents, the bacterium anthrax for instance.

Biological Attacks Difficult to Mount

Whether smallpox, anthrax, or another organism is used, it seems it's only a matter of time before a biological attack occurs. Wheelis agrees with this predominant view. "I think a biological attack against a major American city within the next few years is probable, but it's also probable the results won't be the Armageddon newspapers describe. Instead of thousands of anthrax cases there will be a few dozen." To support his statement, Wheelis describes the difficulties bioterrorists must overcome to mount a successful attack.

"It's not easy these days to get lethal microbial agents and it takes a certain level of microbiological expertise to grow a substantial supply and keep it uncontaminated. Viral agents are especially difficult."   -- Mark Wheelis

"First, the terrorists are in danger themselves. They would need to be immunized or live with the hazard of infection. Second, they would have to acquire the biological agent and be able to grow it in sufficient amounts for an effective attack. Third, they would have to disperse the agent in a way that would get to the target population."

None of these are insurmountable obstacles, but they're not inconsiderable either. Wheelis remarks, "It's not easy these days to get lethal microbial agents and it takes a certain level of microbiological expertise to grow a substantial supply and keep it uncontaminated. Viral agents are especially difficult. Also, if the terrorists are planning to release the agent as an aerosol, they can't just buy a paint sprayer and have it emit particles in the right size range. If anthrax particles are too big they can't enter the lungs where infection begins."

Wheelis admits a bioterrorist attack could be devastating if properly designed, but points out that "Since WW II there have been only two confirmed unnatural outbreaks of disease. One was an outbreak of salmonella, the bacteria that causes food poisoning, in The Dalles, Ore., about 10 years ago. Cult members deliberately instigated the attack to test whether it would keep voters home and thus disrupt local elections."

The second incident was an outbreak of anthrax in Sverdlovsk, now Ekaterinburg, Russia, in 1979 that U.S. intelligence alleged was an accidental release from a Soviet microbiology facility. The Soviet Union denied this allegation for years. With glasnost, Western scientists were allowed into Sverdlovsk to perform an epidemiological survey. Their findings built a compelling case for the anthrax outbreak being an accidental release of spores.

Public's fear excessive

The paucity of substantiated intentional biological attacks may be reassuring, but the United States has "created a monster by our public agonizing over the country's vulnerability," Wheelis maintains. "We've publicized our vulnerability to such an extent that every terrorist in the world must have taken notice. Essentially we've invited a biological attack. Regrettably, this is one of the costs of a free press."

Revealing the country's vulnerability has had a second consequence according to Wheelis. "The public is scared beyond what is reasonable. It's not that a biological attack couldn't have apocalyptic results, it's just very unlikely. Furthermore, if it does happen we can't do anything about it."

While Wheelis' statement sounds fatalistic, he means that people need to understand the reality of preparing for an attack. He explains, "There's no way we can quickly ramp up our public health and emergency systems to respond to a thousand cases of anthrax in Washington, D.C., or 100 cases of smallpox. We're currently trying to prepare for a public health disaster far beyond our capacity. We should focus instead on preparing for small- or medium-scale events for which it's possible to develop attainable plans."

Obviously, preventing an attack would be preferable, and the United States has increased its surveillance of countries likely to stage a biological attack. Unfortunately, discovery of Iraq's biological weapons program provided a sobering lesson.

"The United States had no idea how advanced Iraq's program was," comments Wheelis. "Intelligence agencies completely missed many of the facilities Iraq used for large-scale biological production. The U.S. State Department now estimates that a dozen, or as many as two dozen, countries may be actively pursuing the production of biological weapons. It's a fairly tense time with regard to proliferation."

New treaty on biological weapons

A treaty currently being negotiated in Geneva, Switzerland, would strengthen the 1972 Biological and Toxin Weapons Convention, which called for the termination of all research on offensive bioweapons and the destruction of existing stocks of agents, but contained no mechanism for verifying compliance. In part, the new treaty would allow teams of international inspectors to visit facilities, such as vaccine plants, to ensure they're not a cover for biological weapons production. This July, Wheelis is traveling to Geneva to help organize a Federation of American Scientists panel, which will give a presentation to diplomats negotiating the treaty. The presentation will address peaceful uses of microbiology.