The fierce public debate about recent studies that made bird-flu virus more transmissible has now prompted the world's leading virologists to halt such research for 60 days. And some of those scientists have asked a federal panel that called for censoring such work to reconsider, something the panel will take up as soon as next week.
This past fall, two laboratories reported that they had engineered the virus, which in nature mainly infects birds, to make it easily transmissible through the air among mammals. They did so, researchers said, to highlight the dangers of a pandemic by showing that change was possible with just a few mutations, something scientists did not know. But the National Institutes of Health and its advisory panel on biosecurity responded by telling the scientists to omit key details from papers on the work, out of a fear that a terrorist could use them to make a deadly plague.
The virologists calling for the moratorium do not agree with those actions but say they understand the concerns. "We would like to assure the public that these experiments have been conducted with appropriate regulatory oversight in secure containment facilities" and "need to clearly explain the benefits of this important research and the measures taken to minimize its possible risks," the group of 39 scientists wrote in a joint statement published on Friday by the journals Science and Nature. The signers represent most of the laboratories conducting research into the H5N1 avian influenza virus.
In the statement, the group said it had agreed to halt for two months any work that makes the virus more transmissible in mammals, and to use that time to organize an international forum to debate those issues, probably under the auspices of the World Health Organization.
Paul Keim, acting chair of the National Science Advisory Board for Biosecurity and a biologist who studies anthrax and other deadly agents at Northern Arizona University, said his board, which recommended the partial censorship, would favor such a moratorium. Added Jeffrey F. Miller, another board member and a professor of microbiology at the University of California at Los Angeles: "It's important to have some period of international engagment on this issue to consider how to manage this."
Adding to the pressure this week, a group of 18 scientists wrote to the biosecurity board to say that censoring the papers would do more harm than good, and asked the board to reconsider. In particular, the scientists take issue with the claim, key to the panel's risk-benefit analysis, that bird flu kills 60 percent of infected humans. Vincent R. Racaniello, a virologist at Columbia University and a co-author of the letter, has argued that the danger is overstated, because the real number of infections is unknown; the 60-percent figure, he said,, reflects only a few serious cases that usually end up in hospitals.
Mr. Miller said the panel would take up the request "as soon as possible, probably early next week." He said that "it was a very thoughtful letter, written by experts in the field. And it's important for the board to listen to the community."
The papers, by researchers at the University of Wisconsin at Madison and at the Erasmus Medical Center, in the Netherlands, were about to be published by Nature and Science, respectively, until the board asked them hold back. "It was a very difficult call," Mr. Miller said, adding that "uncertainty over the transmissibility, infectivity, and virulence were the dominant factors" in the decision.
