XK and influenza: These sequences were available for the HA and NA segments, including three antigenically distinct influenza vaccine reference strains selected for 2006–2007 (A/New Caledonia/20/1999), 2007–2008 (A/Solomon Islands/3/2006), and 2008–2009 (A/Brisbane/59/2007) (Figure 1) [30],[33],[34].