The current epidemic of the highly pathogenic H5N1 strain of avian influenza, with a mortality of 58%, appears relentless in Asia, particularly in Vietnam and Thailand.1 Although inefficient, there is some evidence of human-to-human transmission for the H5N1 virus.2 A possible catastrophic pandemic could, therefore, emerge should re-assortment of viral antigens occur resulting in a highly infectious strain of H5N1. Influenza pandemics in 1917–18, 1957–58, and 1968–69 have already caused approximately 15, 4, and 0·75 million deaths worldwide, respectively.
PIIS0140673605670808.pdf