Fig 1.

Phylogenetic relationships among 54 H5-type avian influenza virus hemagglutinins, including those used in this study. Shown in light grey font are AI virus strains used as sources of DNA vaccine (A/Hanoi/30408/2005), challenge virus (A/chicken/Pennsylvania/1370/1983), hemagglutination inhibition assay virus (A/chicken/Vietnam/14/2005), and recombinant protein used in ELISA or cELISA (A/turkey/Ontario/7732/1966), as well as the virus used to produce the cELISA monoclonal antibody (A/turkey/Ontario/6213/1966) (see details in Materials and Methods).