LONDON Any number of laboratories worldwide could engineer bird flu viruses into bioterror weapons capable of causing a human pandemic, and U.S. government efforts to censor research might only increase the risk that rogue elements may give it a try.
Experts say an unprecedented request by the U.S. National Science Advisory Board for Biosecurity (NSABB) for two leading scientific journals to withhold details of research into H5N1 bird flu is unlikely to block anyone already intent on evil.
Yet ironically, the fact that the potential for H5N1 to be deliberately engineered into a highly pathogenic form has become headline news might put fresh thoughts into the wrong minds.
"Anything like this has the potential to trigger ideas in some maverick," said Peter Openshaw, director of the centre for respiratory infection and Britain's Imperial College.
"There are many crazy people out there, and there are also people who are fixed on some idea at the extreme end of the political norm. Both groups have the potential to cause harm."
H5N1 bird flu is extremely deadly in people who are directly exposed to it from infected birds.
Since the virus was first detected in 1997, about 600 people have contracted it and more than half of them have died. But so far it has not mutated into a form that can pass easily from person to person.
Scientists around the world have been working for many years trying to figure out which mutations would give H5N1 the ability to spread easily from one person to another, while at the same time maintaining its deadly properties.
The U.S. National Institutes of Health funded two research teams, one in The Netherlands and one in Wisconsin in the United States, to carry out research into how the virus could become more transmissible in humans.
The aim was to gain early insight on how to contain the public health threat if such a mutation occurred naturally, but now the NSABB says it wants publication of the studies censored to stop the information falling into the wrong hands.
"It's very important work that has shown that with relative ease it is possible to mutate H5N1 into a mammal-to-mammal transmissible virus," said Openshaw.
Wendy Barclay, an expert in flu virology at Imperial College, said stopping the Science and Nature journals from publishing full scientific data from the work would do little more than set an uncomfortable precedent.
"The exact mutations that made this transformation possible were not particularly novel or unexpected so anyone with a reasonable knowledge of influenza virology could probably guess at them if they so wished," she said.
"I'm not convinced that withholding scientific know-how will prevent the highly unlikely scenario of misuse of information, but I am worried that it may stunt our progress towards the improved control of this infectious disease."
Scientists agreed on the need to maintain high levels of safety and security around labs working with dangerous viruses, and be cautious about deliberately doing things that enhance their pathogenicity and disease potential.
One the other hand, seeking to impose unprecedented levels of regulation on laboratories and scientists who proceed with extreme caution anyway is unlikely to have a positive impact.
"Whatever regulations are put in place in sensible, well-run labs in the developed world, we have no way of regulating what goes on in facilities in China or Korea, or possibly in India and Pakistan," said Openshaw.
He pointed out, however, that as a weapon, a mutated H5N1 virus would be pretty unsophisticated and virtually impossible to target at any one group or population.
In contrast, the anthrax powder attacks in the United States
in 2001, which prompted the formation of the NSABB, were able to be highly targeted by the perpetrators who sent the powder in letters to particular groups and individuals.
"(With H5N1), you'd really have to have a grudge against the whole of humanity," Openshaw said.
"These would be very indiscriminate bioweapons that couldn't be controlled. They wouldn't be selective. So it would be a very bizarre decision for someone to release an agent like this, because it would cull humanity."
(Reporting by Kate Kelland)