Fig. 1

Phylogenetic tree of HA1 sequences of influenza B viruses. It’s indicated influenza virus B diverging into two lineages co-circulating around the world, named as Yamagata lineage and Victoria lineage
Phylogenetic tree of HA1 sequences of influenza B viruses. It’s indicated influenza virus B diverging into two lineages co-circulating around the world, named as Yamagata lineage and Victoria lineage