Secondary: To assess the immunogenicity of the VAX125 vaccine delivered i.m. in a single dose regimen at dose levels of 0.1 µg, 0.3 µg, 1 µg, 2 µg, 3 µg, 5 µg, and 8 µg, for inducing a post-vaccination serum HAI antibody response in healthy adults against the influenza A virus H1 HA.