'Killer flu' Oct 23, 2004 10:24:16 GMT -5
Post by Big Bunny on Oct 23, 2004 10:24:16 GMT -5
Easing bio-security on flu virus raises concerns
TORONTO — The decision by a team of U.S. researchers to ease bio-security precautions for a reconstituted version of the 1918 pandemic flu virus - the most lethal killing machine in viral history - is sparking debate within the international scientific community.
Fears that a genetically engineered cousin of the virus responsible for the infamous Spanish flu might accidentally escape from a lab have led to calls within the scientific world for a international meeting to iron out the conditions under which it can be studied.
"Obviously any chance of escape of a virus of that nature would be really very worrying indeed," Australian virologist John Mackenzie said Thursday. The virus was made at the National Microbiology Laboratory in Winnipeg.
The head of the World Health Organization's global influenza program said he isn't certain that work on the virus needs to be restricted to the most secure facilities, but the agency would be open to hosting a forum on the issue.
"What we mustn't forget is that what they're working on is not the 1918 virus," Dr. Klaus Stohr cautioned in an interview from Geneva.
"(But) if we find ... some disagreement internationally on which level of bio-safety is the appropriate one, then we would definitely consider pulling a group of experts together and come up with a WHO opinion on this subject."
The WHO estimates the 1918-19 pandemic, caused by an H1N1 influenza virus, claimed between 20 million and 50 million lives worldwide.
Scientists drawn into the debate are quick to insist they are not accusing lead researcher Yoshihiro Kawaoka of the University of Wisconsin of bad judgment. Kawaoka has a reputation for caution among his peers.
"It's not like he's sort of the cowboy running around doing these experiments," said Richard Webby, an influenza virologist at St. Jude Children's Research Hospital in Memphis, Tenn.
Webby praised Kawaoka for building the recombinant virus in a bio-security level 4 facility (the most secure level) at the Winnipeg lab. Other teams that have worked on variations of the 1918 virus have done so in level 3 facilities, he pointed out.
Still, Webby said his institution wouldn't work with a 1918 variant in anything less than a level 4 lab. It's a view shared by Dr. Frank Plummer, director of the Winnipeg lab.
"We're more comfortable working on it in level 4," Plummer said. Asked why, he simply answered: "Concerns about safety and just being ultra cautious."
Kawaoka, who was travelling in Asia and not available Thursday, is based at the University of Wisconsin in Madison. His work continues at a Level 3Ag - basically a Level 3-plus - laboratory there.
Before moving to that level, his team tested the virus's susceptibility to anti-viral drugs in mice. They also tested the protection offered by flu vaccines, determining that vaccines for contemporary H1N1 strains protected about 70 per cent of exposed mice from developing disease.
"We essentially reassessed the risk of the (future) experiments based on the new information," Kawaoka told a meeting of the U.S. National Institutes of Health recombinant DNA advisory committee in late September.
"I should mention that the experiments were done only in mice and we do not know to what extent the mouse data can be extrapolated."
The decision to work on the virus in a Level 3 lab is in complete accord with U.S. recommendations.
"You may criticize the regulations, but he's certainly acting within the U.S. regulations," Plummer said. "That may change. I know there has been debate in the U.S. about what level of containment is appropriate."
That debate has been reflected in a thread on ProMed, an electronic forum maintained by the International Society for Infectious Diseases.
"A valid risk assessment of the consequences of release would dictate that this research be carried out in a certified maximum containment (BSL4) facility," wrote biosafety consultant M.E. Kennedy, former biosafety director of the Laboratory Centre for Disease Control, the precursor to the Winnipeg lab.
There is precedent for concern. Two lab accidents in China earlier this year sparked a new cluster of SARS cases. And it is believed the H1N1 influenza virus, which stopped circulating in 1957, was reintroduced into humans in 1977 through a lab accident.
Still, all involved in the debate know adding theoretical protection will come at a practical cost.
"It certainly would impede science. It would slow it down considerably," Plummer said.
"So that's what you have to balance it against. The biosafety-biosecurity dimension versus the speed of progress on understanding this virus better."