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Building a deadlier mouse disease

Scientists in St. Louis have created a genetically altered strain of mousepox virus _ a close relative of the smallpox virus _ that is so potent it kills mice vaccinated against the mouse disease, rekindling concerns that some avenues of biotechnology research may be generating lethal knowledge useful to bioterrorists.

Health officials emphasized that the federally financed work posed no threat to people. Although the mousepox virus is highly contagious and lethal in mice, it does not cause illness in humans.

But given the similarities between the mousepox and smallpox viruses, scientists said, the same technique might be useful for making a beefed-up strain of smallpox virus that could kill people despite their having been vaccinated.

The lead researcher, virologist Mark Buller of Saint Louis University, said he has already heard from many people distressed about his work, details of which he presented at a scientific meeting in Geneva recently. "I've received all this hate mail," he said.

He added, however, that others have done much the same thing in other labs. The big difference, Buller said, is that his effort was aimed not just at making bad viruses but also at finding a treatment that would work against them. And happily, he reported, he was successful.

The research and its reverberations in recent days highlight an ongoing debate in the scientific community, the federal government and the public about the relative risks and benefits of microbiological research that might be adapted for bioterrorism purposes.

Since the anthrax attacks of 2001, the government has looked for ways to curb the dissemination of new and dangerous knowledge about disease-causing organisms.

Earlier this month, the National Research Council, an independent congressionally chartered advisory group, recommended steering clear of major research restrictions and instead creating a new level of federal review for proposed experiments that pose particular biosecurity risks _ including any research that aims to make microbes more virulent or resistant to vaccines. That system is not in place yet, though federal officials say they're working quickly to implement it. If it were, scientists agreed, Buller's research clearly would have triggered an extra review.

What Buller did was insert an extra gene into the mousepox virus _ a gene that can suppress the immune system of the mouse that the virus is infecting, thus making it easier for the virus to overcome that animal's defenses.

Buller said Friday that he has "absolutely no biosafety issues" with his work. The mousepox virus doesn't infect humans, the gene involved is specific to mice, and the work had been done by others before.

"The things we did to make that virus more virulent is kindergarten stuff," he said.