WASHINGTON, Nov. 1 (Xinhuanet) -- Researchers in the United States have created a genetically altered mousepox virus so potent that it kills vaccinated mice, raising new concerns that biotech advances may be misused by terrorists, The Washington Post reported Saturday.

　　The research, led by Mark Buller of Saint Louis University, involved inserting an extra gene that can suppress the immune system of the mouse into the mousepox virus, thus making it easier for the virus to overcome the animal's defenses.

　　This was not the first time such work had been done. In 2001, Australian researchers accidentally achieved a similar feat, but what Buller has created was more deadly.

　　In his experiments, all the mice infected with the engineered mousepox virus died.

　　US health officials emphasized that the federally financed workposed no threat to people, saying that although the mousepox virusis highly contagious and lethal in mice, it does not cause illnessin humans.

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

　　Acknowledging that someone could, in theory, apply similar techniques to smallpox, Buller said he had no qualms about presenting his findings because his team had found two different ways of countering the enhanced virulence with drugs and vaccines, and is close to perfecting a third way.

　　Lawrence Kerr, assistant director for homeland security in the White House Office of Science and Technology Policy, praised Buller's work.

　　"This is the type of research we view as critically important to this nation's biodefense research-and-development portfolio," Kerr said.

　　Buller "was developing countermeasures to a model of a very dangerous pathogen and doing everything in a completely safe mouse model," he added. Enditem