Some bird flu strains only three mutations away from a pandemic
new study raises concerns that it may be possible for airborne transmissible, human-to-human avian H5N1 flu viruses to evolve in nature.
The study looked at five mutations identified previously in the controversial bird flu studies published in the journals Nature and Science—led by Yoshihiro Kawaoka of the University of Wisconsin and Ron Fouchier of Erasmus Medical Center in Rotterdam, the Netherlands, respectively—which would make it possible for bird flu to spread from human to human.
In those studies, the researchers experimented with bird flu strains to show which mutations would be necessary for the virus to evolve to become transmissible between mammals.
The papers revealed with only five mutations (amino acid substitutions), or four mutations plus reassortment, bird flu can become transmissible between mammals – and potentially humans. Currently, bird flu can be transmitted from birds to humans, but not from humans to humans.
U.S. federal officials initially asked the journals to withhold publishing the papers, based on bioterrorism fears, but relented after an independent panel of experts determined there was no threat to public health.
Read more: http://www.foxnews.com/health/2012/06/21/how-likely-is-human-bird-flu-pandemic/?test=latestnews#ixzz1yXj7BgGK