It’s a rare kind of research that incites a frenzied panic before it is even published. But it’s flu season, and influenza science has a way of causing a stir this time of year.

Epidemiologists have long debated the pandemic potential of H5N1, aka bird flu. On one hand, the virus spreads too inefficiently between humans to seem like much of a threat: it has caused fewer than 600 known cases of human flu since first emerging in 1997. On the other hand, when it does spread, it can be pretty deadly: nearly 60 percent of infected humans died from the virus. For years the research has suggested that any mutations that enhanced the virus’s ability to spread among humans would simultaneously make it less deadly. But in a batch of studies submitted for publication late last year, two scientists—Yoshihiro Kawaoka of the University of Wisconsin–Madison and Ron Fouchier of Erasmus Medical Center in the Netherlands—have shown otherwise.

Working separately, they each hit on a combination of mutations (five, in Fouchier’s case) that enables H5N1 to spread readily between humans without making it less deadly.

Efforts to publish those findings have been fraught. Critics say that making the methodology or gene sequences widely available amounts to giving would-be bioterrorists an easy recipe. They also worry that these man-made strains might escape from the lab.

Proponents counter that the threat of a global pandemic, were this mutated strain to arise in nature, is far greater than the threat of bioterrorism. Understanding what combination of mutations could transform H5N1 into a human pandemic virus gives epidemiologists a leg up on preparing countermeasures; they can, for example, test existing vaccines against the new strain.

As of mid-December, both papers were being reviewed by the government’s National Science Advisory Board for Biosecurity (NSABB). In the meantime, most experts agree that we need a better way.

“Physicists have been doing sensitive, classified work for 70 years,” says Michael T. Osterholm, an infectious disease expert at the University of Minnesota and a member of the NSABB. “We have to find a way to do the same in the health sciences, without compromising our safety and security.”