To obtain greater resolution, we also estimated phylogenetic trees that included 104 whole genome A/H3N2 influenza viruses sampled globally from 2003–2006 [36], as well as the HA and NA sequences from the A/H3N2 components of influenza vaccines selected for the 2006–2007/2007–2008 (A/Wisconsin/67/2005) and 2008–2009 (A/Brisbane/10/2007) seasons [30],[33],[34]. The gene discussed is XK; the disease is influenza.