Jackson and his colleagues immediately realized the implications with respect to smallpox and its potential as a biological weapon. "We'd come up with, at least with mousepox, a highly effective mechanism for increasing lethality of a virus for genetically resistant animals," he explains. In short, they had stumbled on what might prove a relatively simple way to bolster the killing power of smallpox, already one of the most feared viruses of all time.

Soon the researchers would have data that were even more alarming. The mice, they realized, had died because the IL-4 had undermined their production of killer cells too well, leaving the animals vulnerable to a disease they were normally able to resist. What would happen, they wondered, if they vaccinated Black 6 mice against mousepox before injecting them with the IL-4 version of the sterilizing virus?

By November, Jackson had the results: even in vaccinated mice the mousepox with IL-4 was lethal 60 percent of the time. He immediately went upstairs to Ramshaw's office to convey the news. "Oh, boy," Ramshaw said. "What have we created here?"

Again, the implications regarding smallpox were inescapable. The vaccine against smallpox was so effective that the World Health Organization eradicated variola from the human population more than two decades ago, and routine vaccinations were halted. All stockpiles of the virus were destroyed, save for two: one in a laboratory in Atlanta, Georgia, the other in a lab in Koltsovo, Russia. Mass vaccination would be our most effective defense should terrorists (or "rogue nations") obtain smallpox and use it as a weapon. But a version of variola containing IL-4 might render that defense useless.

Jackson and Ramshaw knew that the bio-weapon they had created to combat common pests—a weapon whose mechanism might be used to intensify a host of human diseases, not just smallpox—fundamentally altered the world's terror equation, much as suicide hijackers did again three years later. What they did not know was how to handle their findings, or even whether to publish them at all—a quandary that molecular biologists will increasingly face. Their uncertainty would be borne out: when they did publish their results, in February of last year, they found themselves at the center of a media storm that distorted many of the details and implications of their work. People would soon begin imagining the worst: terrorists unleashing a virulent disease and public-health officials mounting enormous vaccination campaigns, only to see those vaccinated rapidly succumb; health-care workers dying by the hundreds; panic sweeping the populace, with some people blocking access to their communities and others taking to the backwoods with food and weapons in an effort to escape. Moreover, the media's handling of the story would muddy a vital discussion about how to gauge the threats posed by natural and engineered bio-weapons and how to determine what steps scientists, policymakers, and the public should take.

The Perils of Playing Ostrich





The mousepox-IL-4 results surfaced at a time when the public had an unusually hearty appetite for such information. The late 1990s had brought startling revelations about bio-weapons programs in the former Soviet Union and Iraq, along with rising concerns about emerging viruses such as Ebola and West Nile. Some scientists had begun to discuss the potential of genetic engineering to create bugs that could cause mayhem. Steven Block, a biophysicist at Stanford University, quickly established himself as a leading oracle of doom, albeit one with a carefully reasoned argument based on cutting-edge science.