Table 1. Number of influenza B lineage isolates included for phylogenetic analysis, northern Viet Nam, 2007–2014 (n = 64).

Year	Number of influenza B isolates selected for haemagglutinin gene analysis
	Victoria lineage	Yamagata lineage	Total
2010	3	2	5
2011	14	8	22
2012	7	7	14
2013	4	4	8
2014	11	4	15
Total	39	25	64