[From fowl plague to influenza pandemic; a reason for taking precaution]

Throughout Eastern Asia, there is currently an epidemic of fowl plague or highly pathogenic avian influenza, on an unprecedented scale. The prospects for rapid containment are poor. The causative virus, influenza A of the H5N1 subtype, is of limited infectivity for humans. If infection occurs, however, then the consequences are serious and even fatal in a majority of cases. In view of the receptor specificity of avian influenza viruses, this may be related to individually increased susceptibility, which does not lead to further spread. However, it is known that influenza A viruses can readily adapt to replication in the human host by the acquisition of specific gene segments or even by mutations of the avian virus. The extreme scale of human contact with influenza virus of the H5N1 subtype at present engenders fear that there is a high risk of such adaptation and a subsequent pandemic spread. Adequate precautions are necessary, not only in terms of an acceleration of vaccine production but primarily in arranging for sufficient availability of the new antiviral drugs.