The use of conventional immunologic adjuvants in DNA vaccine preparations

The term "adjuvant" originates from the Latin word adjuvare, which means to help or aid. An immunologic adjuvant is defined as any substance that acts to accelerate, prolong, or enhance antigen-specific immune responses when used in combination with specific vaccine antigens (1). In a broad sense, immunologic adjuvants include certain cytokines and other immunomodulatory molecules (i.e. chemokines and costimulatory factors) or their expression vectors. Since these adjuvants are described elsewhere in this book, here, we are concerned only with adjuvants that are derived from microorganisms and plants or are synthesized chemically.