Most human cases of avian flu have been acquired through close contact with birds but now researchers have created a virus in the lab capable of being transmitted from human to human with just four mutations.
The research also identified the mechanism by which the H5N1 virus (a specific strain of the bird flu) transmits, which may lead to effective treatments or prevention. This should not be confused with the recent swine flu outbreak caused by the H1N1 virus.
Citing safety concerns, a government review panel originally blocked the information from public release. That decision was recently reversed.