some of the recent strategies for the design and production of novel vaccines. The advent of recombinant DNA technology has stimulated the production of several subunit vaccines. In spite of the obvious advantages to this approach, the limited immuno­ genicity of many subunit candidates has hindered their development. Strategies to enhance the immunogenicity of subunit vaccines is therefore critical. Several approaches toward this goal, including design of novel adjuvants and delivery systems as well as design of advantageous carriers, are presented here. Among the carriers evaluated here are polypep­ tides (flagellin, HBV core antigen, J3-galactosidase), attenuated virions (Vaccinia, Sindbis), and nonpathogenic licensed bacteria (Salmonella).