 Study Design: This is a Phase I double-blind, placebo-controlled study to evaluate safety, tolerability, and immunogenicity of a recombinant DNA vaccine against the influenza virus hemagglutinin H5. The hypothesis is that this vaccine will be safe for human administration and will elicit antibody and T cell responses against the H5 protein. The primary objectives are to evaluate the safety and tolerability of the investigational vaccine at a 1-mg and 4-mg dose in healthy adults. Secondary and exploratory objectives are related to the immunogenicity of the study vaccine. 