Global Security Newswire

The head of a U.S. biodefense panel on Tuesday said two teams of scientists had demonstrated how to defeat a naturally occurring impediment to the spread of the avian flu virus, creating the potential for a disastrous pandemic in the event of a modified pathogen's mistaken or deliberate transfer into the environment, the Center for Infectious Disease Research and Policy reported (see GSN, Jan. 31).

The National Science Advisory Board for Biosecurity last year called for two scientific journals to keep some information out of research papers produced by scientists at the University of Wisconsin (Madison) and the Erasmus University Medical Center in the Netherlands. The separate research efforts produced highly contagious versions of the bird flu. The papers have not yet been published.

"The artificial evolution of a new mammal-adapted H5N1 virus, as reported in these two papers, has removed the natural barriers that might have existed. Accomplishing this in the lab, however, doesn't mean that it can occur naturally," acting panel head Paul Keim told the journal Nature.

Though the Wisconsin team's virus did not demonstrate lethality in animal trials like its counterpart produced in the Netherlands, "we believe that the techniques described could be used to generate other viruses with [modified genetic material from the H5N1 virus] that have potentially much greater pathogenicity," Keim said (see GSN, Jan. 26). The limited spread of the H1N1 swine flu in 2009 cannot accurately predict the spread of related viruses through populations with less immune resistance to such pathogens, he added.

"The fact that [the Wisconsin study's] specific virus and mutations might not be the feared H5N1 pandemic strain is not the point. It is that this laboratory created a virus that has now bypassed apparent barriers to evolution in the wild. If this virus were to escape by error or by terror, we must ask whether it would cause a pandemic. The probability is unknown, but it is not zero," he added.

The U.S. flu research "significantly advances the ability to construct an H5 virus with catastrophic potential. This altered H5 HA gene could be combined with other influenza virus genes possibly leading to a pandemic," he said.

Instances of the pathogen's intentional weaponization would be "low-probability events, but they could introduce a new evolutionary seed into the environment that seems not to exist in nature. This might not cause a pandemic instantly, but it could start the virus on a new path for pandemic evolution," he said, noting H5N1 flu vaccinations and countermeasures are available but unacceptably scarce (Robert Roos, Center for Infectious Disease Research and Policy release I, Jan. 31).

Separately, one scientist the panel lacked empirical justification for its call to restrict the release of the research data.

"Extensive serological studies must be done to determine the extent of human infection with avian H5N1 influenza viruses," Columbia University virology expert wrote in a commentary published by mBio. "To think that we can duplicate the enormous diversity and selection pressures that occur in the wild is a severe case of scientific hubris."

The expert advocated full release of details from the studies.

St. Jude's Children's Research Hospital expert Robert Webster, though, defended the panel's decisions in a separate column. H5N1 commonly generates harsher symptoms in humans than in ferrets, the animals tested in the two studies (Lisa Schnirring, Center for Infectious Disease Research and Policy release II, Jan. 31).

The New York Times on Saturday published eight expert commentaries on the issue (Robert Roos, Center for Infectious Disease Research and Policy release III, Jan. 30).