Development of DNA Vaccines for Aquaculture

Abstract

Aquaculture is a rapidly growing industry in many countries (Meyer, 1991; Leong & Fryer, 1993). Its development is driven by an increasing demand for fish and shellfish products, and the continuous decline of wild caught harvests (Meyer, 1991; Hanfman, 1993). However, loss due to infectious disease is a major concern for fish farmers. Approximately 10% of all aquatic animals are lost annually due to pathogens (Leong & Fryer, 1993). For various reasons, such as inefficacy, high cost and/or environmental concerns, traditional antigen-based vaccines (i.e., whole killed, live attenuated and subunits) have only been used successfully for the prevention of a limited number of diseases, mainly those of bacterial origin. DNA vaccination could circumvent many of the disadvantages associated with classical methods of immunization. In mammals and birds, they have been shown to induce very potent, long-lasting and protective humoral and cell-mediated immune responses against numerous viral, bacterial or parasitic diseases (Wahren, 1996; Donnelly et al., 1997; Davis & Brazolot Milian, 1997).