Whither 2009 H1N1?
When will the 2009 swine-origin influenza virus become a seasonal strain? While prediction is very hard, especially of the future (at least according to Yogi Berra), examining past pandemics can be informative. The 1968 pandemic began with the emergence of a novel H3N2 influenza virus in Hong Kong in July 1968. First isolates (stars) were …