DNA inoculation represents a novel approach to vaccine and immune therapeutic development. The direct injection of gene expression cassettes into a living host transforms a number of cells into factories for production of the introduced gene products. Expression of these delivered genes has important immunological consequences and may result in the specific immune activation of the host against the novel expressed antigens. The recent demonstration by laboratories that these immune responses are protective in some infectious disease experimental models as well as cancers is viewed with cautious optimism. Further, the relatively short development times, ease of large-scale production, low development, manufacturing, and distribution costs all combine with immunological effectiveness to suggest that this technology will dramatically influence the production of a new generation of experimental vaccines and immune therapies. It is hoped that DNA inoculation will ultimately lead to new vaccines that are immunologically effective and economically accessible to all nations.