Electroporation has been shown to induce an effective immune response after delivery of DNA vaccines (Peachman et al. 2003; Foldvari et al. 2006; Medi and Singh 2008; Vandermeulen et al. 2009) . For example, studies in pigs have shown the ability of electroporation to deliver HBsAg gene using a single-needle or a six-needle electrode (Babiuk et al. 2002) . Studies have demonstrated that in vivo skin electroporation may be used to increase transgene expression relative to naked DNA injection (Drabick et al. 2001) . Transfected cells were principally located in dermis and included adipocytes, fibroblasts, endothelial cells, and numerous mononuclear cells with dendritic processes in a porcine model. Transfected cells were also observed in lymph nodes draining electropermeabilized sites. A HBsAg-coding plasmid was used to test skin electroporation-mediated nucleic acid vaccination in a murine model. Applications for these findings include modulation of immune responses to pathogens, allergens, and tumor-associated antigens and the modification of tolerance. In another study, in vivo electroporation has shown protection against avian influenza in nonhuman primates (Laddy et al. 2009 ). A number of human clinical trials testing vaccination enhanced by electroporation are currently under way.