The effects of the use of potassium alum adjuvant in vaccines against vibriosis in rainbow trout, Salmo gairdneri Richardson

. A formalized bacterin of Vibrio anguillarum, with and without alum adjuvant, was administered intraperitoneally to rainbow trout under farm conditions. Compared with the normal bacterin the adjuvanted preparation caused pathological changes indicative of chronic peritonitis, substantial early mortalities in 3 cm fish, and to a lesser extent in 20 cm fish, and depressed growth rate. No additional degree of protection against artificial challenge was obtained from its use.