wellness

A Wisconsin virology team that created a more contagious form of bird flu did not produce a highly lethal superflu, as a Dutch team controversially did last year, said the leader of the Wisconsin team.

Dr. Yoshihiro Kawaoka of the University of Wisconsin, Madison and the University of Tokyo said in a commentary published online Wednesday by Nature magazine that his team's virus had infected ferrets through the air but did not kill any of them. Also, he said, "current vaccines and antiviral compounds are effective against it."

By contrast, a virus created by Ron Fouchier of Erasmus Medical Center in the Netherlands had both the high lethality of the H5N1 avian flu and the ability to transmit easily among ferrets, touching off fears that his virus could cause a devastating epidemic in people.

However, a flu expert who serves on a U.S. scientific advisory panel that looked at both Fouchier's work and Kawaoka's said the panel still believes key details should be censored from both papers before they are published, since the gene-manipulation techniques and intermediate mutations are as potentially dangerous as the end products.

Some scientists believe that Fouchier created what is potentially the most lethal virus in history -- a flu that would transmit through a sneeze and kill more than 50 percent of those who caught it. That has led to calls for restrictions. Some have argued that the virus stocks should be destroyed; others want the virus restricted to laboratories with the highest biosecurity levels.

Some scientists, including Fouchier, argue that the fear of his virus is exaggerated. What works in ferrets does not always work in humans, they argue, and the true lethality of avian H5N1 is unknown because there have been fewer than 600 confirmed human cases.

Asked whether it was possible that his virus could be passed around among laboratories for further work while Fouchier's virus ought to be more highly restricted, Kawaoka said, "That judgment has to be made in discussions with the international scientific community."

Richard H. Ebright, a chemistry professor and bioweapons expert at Rutgers University who has long opposed unrestricted research into making flu viruses more lethal, said his impression was that Kawaoka's virus was less lethal than Fouchier's, but that if the only vaccine against it was an experimental H5N1 vaccine that is not widely stockpiled, "it still has significant pandemic potential."