This study aimed to evaluate the immune effects of the triple vaccine against Vibrio parahaemolyticus,Vibrio alginolyticus,and Edwardsiella tarda in turbot(Scophthalmus maximus).Turbot were immunized by oral administration,intraperitoneal injection,and immersion methods.Indirect ELISA was employed to measure the antibody levels in the serum,skin mucus,and hindgut mucosa.V.parahaemolyticus,V.alginolyticus,and E.tarda were used for challenge experiments,and the relative survival rate of turbot was determined.The results showed that the intraperitoneal injection group had the highest antibody titer in the serum.Antibodies were detected in the skin mucus only in the immersion group.The antibody titer in the hindgut mucosa was the highest in the oral administration group.The results of challenge experiments showed that the relative survival rate was 40%-50%in the intraperitoneal injection group and the immersion group,while it was 50%-60%in the oral administration group.The triple vaccine for oral administration was coated with acrylic resin,which prevented the digestion by gastric juice and enabled the release in the hindgut,effectively preventing turbot infections by V.parahaemolyticus,V.alginolyticus,and E.tarda.
