The effect of levamisole as an adjuvant on the humoral immune response of Atlantic salmon (Salmo salar L.)

Pre and post-smelt Atlantic salmon (Salmo salar L.) were administered a lev amisole adjuvanted Vibrio anguillarum vaccine by bath or intraperitoneal (I P) injection. A significant serum anti-V anguillarum antibody response was elicited in groups of fish administered an IP injection of bacterium only. Fish (pre and post-smelt) treated with the levamisole adjuvanted vaccine (I P and bath) showed a suppressed response relative to the respective positiv e (vaccinated) control groups. No detectable antibody response was elicited in fish not treated or treated with a placebo. Results from this trial sug gest that levamisole as an adjuvant has a narrow range of efficacy.