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

Pre and post-smolt Atlantic salmon (Salmo salar L.) were administered a levamisole adjuvanted Vibrio anguillarum vaccine by bath or intraperitoneal (IP) 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-smolt) treated with the levamisole adjuvanted vaccine (IP and bath) showed a suppressed response relative to the respective positive (vaccinated) control groups. No detectable antibody response was elicited in fish not treated or treated with a placebo. Results from this trial suggest that levamisole as an adjuvant has a narrow range of efficacy.