TORONTO - Future work on mutated bird flu viruses should only take place in laboratories with the highest level of biosafety, suggests a new commentary on the controversy over two studies that led to the creation of these viruses.
But an opposing view argues that to restrict work on the viruses to so-called BSL4 labs would not leave the world safer, but would impede the quest to find out how flu viruses that normally infect birds can adapt to infect people.
The point-counterpoint pieces are published Tuesday in mBio, a journal of the American Society for Microbiology.
The two studies, by Dutch and American researchers, are at the heart of an unprecedented controversy in life sciences. The unpublished works, conducted independently of one another, report on how H5N1 flu viruses can be pushed to become transmissible by aerosols -- the equivalent of coughing and sneezing -- in ferrets. Ferrets are considered the best animal model for predicting how flu viruses will behave in humans.
The two teams of scientists are eager to publish their work, saying those doing surveillance on H5N1 viruses in places where the viruses spread in poultry and wild birds need to know the combination of mutations that can transform the virus from one that doesn't spread from mammal to mammal to one that can.
But a group of experts that advises the U.S. government on issues of biosecurity deemed the work too dangerous to publish in full, saying the risks of putting the information into the public domain outweigh any benefits the work might garner. The editor-in-chief of mBio, Arturo Casadevall, is a member of that group, the U.S. National Science Advisory Board for Biosecurity.
The dispute over publication has been going on for months. But as it lingers, attention is starting to shift to what should be done with the viruses the Dutch and American teams created. Should additional work on them be allowed? If yes, under what laboratory conditions? Should the source labs be allowed to share the viruses with other researchers in a bid to speed up the acquisition of new knowledge?
The commentaries in mBio don't address all of those questions. But they do weigh in on the conditions under which future work on the viruses should be done.
Adolfo Garcia-Sastre, an influenza microbiologist and co-director for the Emerging Pathogens Institute at New York's Mount Sinai School of Medicine, argues work like this can help scientists evaluate the risks non-human flu strains pose to people.
Little is known, he says, about what makes a flu virus able to transmit effectively in one species but not another. In particular, he says, more research is needed to assess the risk H5N1 viruses pose to humans.
Garcia-Sastre argues that the safety mechanisms and procedures used in BSL3-enhanced laboratories -- the type of lab the American and Dutch teams used to create their viruses -- offers sufficient protection against a possible escape of the viruses.
"As scientists, we have the responsibility to avoid the undue restrictions of the highest level of biocontainment if enhanced BSL3 facilities can provide the appropriate biosafety."
"The use of BSL4 containment would not decrease the risk of virus release any more than enhanced BSL3 containment, but it would result in an unnecessary burden that would restrict research on H5N1 influenza transmission to a few facilities and considerably decrease the speed of research on this important pathogen," he says.
What Garcia-Sastre doesn't say is that neither the American team, from the University of Wisconsin-Madison, nor the Dutch team, from Erasmus Medical Centre in Rotterdam, has a BSL4 laboratory. In fact, few influenza researchers anywhere would have ready access to BSL4 facilities, which are typically used for study of the most dangerous pathogens such as Ebola virus.
Canada has one BSL4 laboratory, at the National Microbiology Laboratory in Winnipeg. The Public Health Agency of Canada has already determined that if any work is done on the lab-made H5 viruses in this country, it will have to be done in BSL4.
In an editorial he co-wrote to accompany the commentaries, Casadevall notes that one could argue that restricting future work on these viruses to BSL4 labs might make the world more vulnerable to H5N1, because there are few BSL4 labs and the facilities are already in hot demand.
"We know from experience with select agent regulations that as research is made more difficult less work is done," Casadevall and Thomas Shank, chair of the publications board of the American Society of Microbiology say.
But a colleague of Casadevall's from the NSABB says the lab-made viruses must be restricted to BSL4. Michael Imperiale, an NSABB member, and Michael Hanna, both of the University of Michigan at Ann Arbor, argue that in making the H5N1 virus transmissible among mammals the two research teams changed its biosafety profile.
"If a BSL3 worker were to be infected with natural H5N1 virus, the infection would likely stop in that individual," they say. "With human-to-human aerosol transmission" -- which the lab-made viruses may be capable of -- "others could become infected."
Hanna is the manager of biological and laboratory safety at the university. Imperiale is a professor of microbiology.
They also note BSL4 labs would have greater physical security, lowering the risk someone might breach the facilities and steal samples of the viruses.
"We owe it to the public worldwide to demonstrate that we are working with these viruses in a responsible manner," Imperiale and Hanna argue.
