Figure 2.

Phylogenetic tree of HA1 nucleotide sequences. Phylogenetic analysis of HA1 nucleotide sequences encoded by equine influenza viruses. The maximum likelihood tree was created by Mega Version 6. Bootstrap values were obtained after 1000 replicates and are shown at major nodes. Phylogenetic groups are shown by continuous bars on the right, as indicated. Representative viruses from each of the 13 premises on which HA sequence data were obtained are included. A/eq/Kilkenny/1/14 and A/eq/Kilkenny/4/14 were identified on a single premises. ♦ represents the strains included in the vaccines.