Bird flu research that was previously considered a national security threat will see the light of day.

The panel of scientists that warned the U.S. government about the dangers of publishing two research papers on H5N1, also known as bird flu, voted Friday to publish revised versions of the papers that no longer contain secrets bioterrorists could use to mutate the virus.

Researchers engineered a mutated virus to better understand how the disease spreads and how lethal it could become.

The National Science Advisory Board for Biosecurity warned the government in December that if the methodology researchers used to mutate the virus into an easily transmissible form was published, terrorists could use it as a blueprint to create a lethal flu pandemic.

On Friday, the advisory board unanimously approved the publication of a revised form of one of the papers and recommended the publication of the second by a vote of 12 to six after the authors removed the step-by-step directions of how to make bird flu easily transmissible in mammals, which is naturally isn't.

The data described in the revised manuscripts do not appear to provide information that would immediately enable misuse of the research, the panel wrote in the decision.

The revisions also clear up misunderstandings in the original version, namely that the mutated virus, which was tested on ferrets, killed every ferret it infected, which is untrue, according to the journal Science.

The virus was fatal to ferrets only after animals were inoculated [through the nose] at extremely high doses, the journal said, according to the Wall Street Journal.

Ferrets infected with doses of bird flu that humans would typically be exposed to did not die.

We have made it clear that the virus is much less lethal than had initially been thought by the NSABB, Ron Fouchier, study author and researcher at Erasmus Medical Center, told BBC News. We have also added data on how we did this work safely and explained better the benefits of the research with respect to pandemic preparation.

The World Health Organization currently recognizes 586 H5N1 human infections, mostly in Asia, and 346 deaths, a fatality rate of 60 percent. The 1918 Spanish flu, which killed 50 million people over the course of a year, had a fatality rate of 3 percent. The seasonal flu has a fatality rate between 0.001 and 0.02 percent.

New evidence has emerged that underscores the fact that understanding specific mutations may improve international surveillance and public health and safety, the panel said. Global cooperation, critical for pandemic influenza preparedness efforts, is predicated upon the free sharing of information and was a fundamental principle in evaluating these manuscripts.

The panel's decision isn't binding -- it still has to go before the U.S. Department of Health and Human Services, which said it will take the panel's recommendation into consideration.

Scientific journals, however, are preparing for imminent publication.

Subject to any outstanding regulatory and legal issues, we intend to proceed with publication as soon as possible, Philip Campbell, editor-in-chief of Nature, told the Associated Press.

Art Caplan, bioethics professor at the University of Pennsylvania, told the Associated Press that much of the information is already being shared among scientists, so trying to squash it is pointless.

The details of this paper are already out, these two papers. The horse is out of the barn, and trying to yank it back doesn't make much sense, he said.