Bird flu mutation studies paused to decide next steps

Scientists studying a more dangerous version of the H5N1 bird flu virus say they'll stop their experiments for 60 days.

Concerns that new version of bird flu could be used by bioterrorists

Scientists studying a more dangerous version of the H5N1 bird flu virus say they'll stop their experiments for 60 days amid debate what to do next.

In a letter published Friday in the journals Nature and Science, the authors said they recognize the need to clearly explain the benefits of the research and to minimize possible risks with input from the scientific community.

"We realize that organizations and governments around the world need time to find the best solutions for opportunities and challenges that stem from the work," the scientists wrote.

"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 scientists created the new version of bird flu while they were researching how mutation of the virus might pose a bigger threat to humans

Ron Fouchier of Erasmus Medical College in the Netherlands, Adolfo Garcia-Sastre of Mount Sinai School of Medicine in New York and Yoshihiro Kawaoka of the University of Wisconsin, Madison, defended the research as key to public health research into understanding the potential pandemic risks of influenza viruses.

Intense debate

Despite the public health benefits that studies are seeking, a perceived fear that the 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.

The researchers said they wanted to assure the public that these experiments have been done with appropriate regulatory oversight at secure labs by highly trained investigators.

The studies aim to see whether influenza-viruses adapted to ferrets have the ability to transmit from human to human.

Ferrets are considered the best animal model for human infection with influenza. 

Last month, the U.S. government, which is funding the research, asked the teams not to reveal the formula for the new version of the H5N1 virus amid worries that it could be copied by would-be bioterrorists. Some critics are also worried an accident could allow the new virus to escape from the laboratories.

The moratorium "is a really good idea, because a lot of very important issues are at hand," said Dr. Anthony Fauci, director of the National Institutes of Heath's National Institute of Allergy and Infectious Diseases.

The H5N1 bird flu only occasionally infects people, mostly those who have close contact with sick poultry.

With files from The Associated Press