Scientists halt controversial flu research

Scientists working on a controversial project to create new forms of H5N1 bird flu agreed on Friday to stop their work for 60 days while the debate plays out.

"We recognize that we and the rest of the scientific community need to clearly explain the benefits of this important research and the measures taken to minimize its possible risks," they wrote in a letter published jointly by the journals Science and Nature.

"We propose to do so in an international forum in which the scientific community comes together to discuss and debate these issues," added the letter, signed by 39 scientists including Ron Fouchier of Erasmus Medical Center in Rotterdam, Adolfo Garcia-Sastre of the Mount Sinai School of Medicine in New York and Yoshihiro Kawaoka of the University of Wisconsin.

"To provide time for these discussions, we have agreed on a voluntary pause of 60 days on any research involving highly pathogenic avian influenza H5N1 viruses leading to the generation of viruses that are more transmissible in mammals," the letter said. "In addition, no experiments with live H5N1 or H5 HA reassortant viruses already shown to be transmissible in ferrets will be conducted during this time."

Late last year the two teams, one led by Fouchier and one by Kawaoka, created lab-engineered forms of H5N1 bird flu. They said they were trying to see how the virus, which has been circulating since the 1990s, might mutate into a form that could cause a deadly human pandemic.

Other researchers expressed fears about the risk the new viruses could accidentally escape and cause the very pandemic that the scientific community has been worried about. In December, the National Science Advisory Board for Biosecurity, an independent group that advises the federal government, asked the two teams to withhold details of their work.

Supporters of the research say it's key to predicting how H5N1 might mutate and change, as flu viruses often do. But opponents have said the work could be misused by terrorists or that the virus might somehow escape from the lab and spread.

The researchers tried to answer these fears in their letter.

"Despite the positive public-health benefits these studies sought to provide, a perceived fear that the ferret-transmissible H5 HA viruses may escape from the laboratories has generated intense public debate in the media on the benefits and potential harm of this type of research," they wrote.

"We would like to assure the public that these experiments have been conducted with appropriate regulatory oversight in secure containment facilities by highly trained and responsible personnel to minimize any risk of accidental release. Whether the ferret-adapted influenza viruses have the ability to transmit from human to human cannot be tested."

Right now, the H5N1 virus only rarely infects humans and cannot be transmitted very easily from one person to another. But it kills more than half its victims, according to the World Health Organization, which has tallied 343 deaths out of 582 known cases.