Controversial bird flu studies that are pitting influenza researchers and scientific journals against biosecurity experts raise complex issues and should not be framed in simplistic terms by proponents or opponents of their publication, a World Health Organization official suggests.

While it's tempting to boil the arguments down to a single issue -- the evils of censorship, the sanctity of open science, the dangers of bioterrorism -- to do so ignores the many difficult questions that the scientific, public health and security worlds need to work through to forge a path forward, Dr. Keiji Fukuda said in an interview with The Canadian Press.

Fukuda, an influenza expert and the WHO's assistant director-general for health security and environment, was commenting on the roiling controversy surrounding two unpublished studies about the H5N1 flu virus.

The studies reportedly detail how researchers in the Netherlands and the United States pushed H5N1 avian influenza viruses to evolve to the point where they became easily transmissible among ferrets. Ferrets are considered the best animal model for predicting how a flu virus will act in people.

The studies, in the publishing pipelines of the journals Nature and Science, drew the concern of an expert group that advises the U.S. on biosecurity issues and so-called dual-use research -- legitimate scientific work that could be used for nefarious purposes.

The National Science Advisory Board on Biosecurity urged the U.S. government -- which followed the advice -- to ask the journals not to publish the guts of the studies, suggesting they are in effect recipes for how to turn H5N1 viruses into a potentially potent bioterrorism weapon.

Now a variety of parties, including the journals and the leading U.S. biomedical research agencies, are trying to figure out how to set up a system that allows the findings to be published in abbreviated form, with the proviso that more detail will be provided on a need-to-know basis to other researchers, public health agencies and potentially others.

The WHO recently weighed in on the heated debate that has ensued, trying, in Fukuda's words, to "bring some balance to the discussion."

The move in part was motivated by concern that the controversy -- and any impact it may have on H5N1 science -- might ground the WHO's efforts to get up and running a critical compromise called the Pandemic Influenza Preparedness Framework that was devised over four painful years of negotiations.

The system is designed to ensure flu viruses with pandemic potential are filtered into international surveillance networks and on to researchers who can study them. In exchange, countries will reap benefits that might include access to pandemic vaccine or funding for surveillance activities provided by pharmaceutical companies that use the viruses to make vaccines.

The framework was approved last May at the World Health Assembly -- the WHO's governing council -- and is in the early implementation stages.

"It's a very delicate period," Fukuda said. "It's a really quite important framework in our viewpoint and something which, if it doesn't get implemented, it's not going to be easy -- and it may be impossible -- to get back to there again."

The WHO is also worried, though, that a tendency to see the controversy through a single frame -- censorship versus bioterrorism, for example -- is failing to highlight the myriad pressing questions that now need answering.

Among them: Now that these viruses exist, what will be done with them? Can they be transported so that other researchers can work with them? If further work is going to be done on them, where will that work be done? Will the methods used be the safest possible?

For instance, Fukuda noted it's being argued that the modified viruses should be studied in animals to see if antiviral drugs and prototype H5N1 vaccines protect against severe disease or infection.

"In principle that sounds good. But where are you going to do it? How are you going to do it? Has that been thought through? If it's going to involve animal studies, are you set up for those animal studies?" he asked.

Other questions that should be considered now -- not after results have been arrived at -- include what will be done with the information further studies generate? If it is also deemed too sensitive from a security perspective, how will it be handled?

One question that is being raised relates to the biosecurity and biosafety designations of the facilities in which work on these viruses is done. Some parties are questioning whether future work on the viruses should be limited to labs with the highest biosecurity protections, Level 4.

H5N1 work is typically done in Level 3-plus labs -- an intermediate step between Level 3 and the highly expensive and cumbersome Level 4, used for the most dangerous pathogens such as the Ebola virus. The Dutch and American research teams did their work under 3-plus conditions, but neither has a Level 4 lab.

Fukuda would not be drawn on the Level 4 question, saying there's no point debating the issue in the abstract.

"I don't think it's so useful for me to opine about BSL 3, 3-plus or 4 without actually knowing about the virus," said Fukuda, who has not seen the studies in question.

He said no single institution or agency can tackle the questions raised by this controversy, but much work is needed from a number of parties to sort through the varied implications of the work.

"It makes sense for us to make sure that we're looking at all the issues, separate out the long-term, the short-term issues and be very clear what it is that we're trying to address before we talk about the solution is this or that," he said.