Bird flu studies at the centre of a heated controversy pose a potential risk to public health of an "unusually high magnitude," the U.S. biosecurity experts who have advised against full publication of the studies said Tuesday.
The U.S. National Science Advisory Board on Biosecurity said emergence of an H5N1 flu virus capable of spreading easily from person to person would be an "unimaginable catastrophe" regardless of whether it was concocted by nature or in an laboratory.
The comments are part of a statement from the 23-member group outlining, for the first time in published form, their rationale for advising the U.S. government to ask the journals Science and Nature to withhold key sections of the two studies.
The journals have tentatively agreed to publish only the findings, if a system can be established to share details of the methods used with researchers and public- health agents on a need-to-know basis.
"We do not believe that widespread dissemination of the methodology in this case is a responsible action," the NSABB members argued in a commentary published in the two journals.
The commentary contained little in the way of new insight. Though this is the first published statement from the group, NSABB members have explored most of the points it contains in media interviews in the weeks since the controversy started to rage.
But a question-and-answer style interview with NSABB acting chair Paul Keim provides a deeper understanding of the board's thinking.
It reveals the NSABB is concerned the two laboratories that conducted the disputed studies have created H5N1 viruses -- or hybrids containing some H5N1 genes -- that bypass what have seem to have been natural barriers to its ability to spread easily in mammals.
(Both groups did work in ferrets, the animal model considered the best for predicting how a flu virus will behave in humans. There is no way to be sure that a virus that spreads easily among ferrets will also do so among people; it would be unsafe and unethical to test whether the viruses the two groups made could transmit readily from person to person.)
Keim noted that the H5N1 virus has been around since at least 1996 and hasn't yet managed to become transmissable among people, perhaps because of "inherent biological limitations."
In reality, while flu researchers have mused about that possibility, science cannot currently say why some flu viruses emerge from nature to successfully infect humans and others do not. Nor can it say that a virus that has not yet made the leap will never be able to do so. If flu viruses have barriers or timetables, they haven't shared that information yet with humans.
The controversy relates to research conducted at Erasmus Medical Centre in Rotterdam, the Netherlands, and at the University of Wisconsin-Madison.
The Dutch work, led by virologist Ron Fouchier, produced a mutated H5N1 virus that spread by the respiratory route -- the equivalent of coughing and sneezing -- in ferrets. The virus was lethal to at least some of the ferrets.
The American team, led by virologist Yoshihiro Kawaoka, produced what's known as a reassortant, a virus containing the hemagglutinin (the H in a flu virus's name) from an H5N1 virus and the seven remaining genes from the H1N1 virus that caused the 2009 pandemic. The resulting virus did not kill ferrets.
Fouchier, who had been waiting to read the NSABB's rationale, was disappointed by the published statement.
"I was hoping for an explanation of the risks of communicating the results of our study via normal publication. There is none," he said in an email.
"Our information is useless to small bioterrorist groups, and larger organizations and rogue countries can replicate our work without our manuscript."
He said based on the points made in the Nature Q-and-A with Keim, several previously published flu studies should not have made it into print. And he worried that the thinking could lead to more frequent demands for redacting manuscripts in future.
Flu scientists, led by Fouchier, announced recently that they will observe a voluntary two-month moratorium on H5N1 transmission studies. One of the journals -- Science -- has agreed to hold off publication until March. Nature is not commenting on its plans.
The idea is to allow international talks on resolving the dispute to get underway. The World Health Organization is facilitating those talks, and has called a small meeting of the research teams, some leading flu experts, the journal editors and a few other key players for Feb. 16 and 17.
Broader issues raised by the controversy will likely be explored at another larger meeting later, the WHO has indicated.
