Analysis of the numbers and influenza B strains of randomly sampled sequences from January 2010 to February 2014.

<p>Number of B/Victoria and B/Yamagata lineage strains found are displayed in red and yellow bars, respectively (left scale). Total number of influenza B positive samples for each year is indicated by dot-line (right scale). The strains B/Brisbane/60/2008, B/Wisconsin/1/2010, and B/Massachusetts/2/2012 included in the Southern hemisphere vaccines for the given year are indicated by the asterisk. Vic denotes Victoria and Yam denotes Yamagata.