The identification of 4 different strainsof H5N1 (the avian flu virus) in southeastAsia has implications for preparation toward off a possible pandemic and the vaccinesthat may be needed to protectagainst human infection, according to theresults of a study reported recently in theProceedings of the National Academy ofSciences.
Researchers have discovered that theH5N1 virus exists commonly in domesticatedpoultry populations and also in wildbirds before they migrate. Using geneticanalysis, the investigators identified 4 sublineagesof the virus existing in birds fromdifferent geographical areas. WhereasH5N1 can be spread over long distancesin migratory birds, in southeast Asia infectedpoultry seem to be the main way thevirus is transmitted. Better surveillance ofbird populations to ensure that one of theH5N1 variants does not begin to spreadmore easily between individuals is a keyrecommendation, noted the researchers.
Lead researcher and flu expert RobertWebster, PhD, said that the findings underscorethe need for a variety of vaccines."Multiple, different vaccines are going tohave to be prepared and held ready incase one of these goes human-tohuman," he said.