Fish vaccine: development, production and use of bacterial vaccines, with special reference to salmon

A limiting factor in cultivation of Atlantic salmon (Salmo salar L.) and other fish species has been diseases. Apart from furunculosis and bacterial kidney disease (BKD) in salmon, vibrio infections are by far the most serious problem in aquaculture. If attacked by a pathogen, the fish may develop a disease as illustrated in Figure 17.1. To combat diseases vaccination has been a great success in human and veterinary medicine. In aquaculture the use of vaccines is still in an early developing phase and, as reviewed by Ellis (1988a), it is mainly vaccines against bacterial infections like vibriosis, cold water vibriosis, yersiniosis and furunculosis that have given convincing protection in field trials. Vaccines against other diseases have been less effective, side effects have occurred, and some vaccines have been too expensive both to develop and produce. However, the economical losses due to cold water vibriosis and vibriosis in salmon aquaculture amounted to more than US$ 100 million during the period 1984–1988 in Norway (Tilseth, Hansen and Moller, 1991), which justifies a rather high price for fish vaccines, if effective. Research into and development of fish vaccines are in our opinion necessary for a healthy aquaculture industry in the future.