Figure 4
From: Assessment of exposure to influenza A viruses in pigs between weaning and market age
Phylogenetic tree of the HA gene nucleotide sequences of H1N1 viruses in the longitudinal study during nursery phase. The isolated H1N1 viruses in Study 2 are visualized in red color (||) and a part of pH1N1 cluster starting with A/SW/ON/148-9/14/H1N1/HA and ending with A/SW/ON/173-9/14/H1N1/HA. Viruses used as reference strains in the hemagglutinin inhibition (HI) assay are labeled with asterisk, including one of the viruses isolated in the Study 2. Labels of the study viruses (e.g. A/SW/ON/148-9/14/H1N1/HA) contain unique pig identifier (e.g., 148 in the latter example), and sampling occasion (e.g., occasion 9 in the latter example). Pigs 148,130, 173 had viruses sequenced on more than one occasion.