The inclusion of FrC sequence, or other nonself antigens, activates T-cell help to reverse tolerance and induces high levels of immunity [47, 64, 65] . To further increase immunogenicity of DNA vaccine, the use of molecular adjuvants such as cytokines and immunomodulatory molecules has been extensively employed in clinical trials [56, [58] [59] [60] [61] [62] [63] 67] .