The efficacy and side-effects of oil-based adjuvants emulsified Vibrio anguillarum bivalent inactivated vaccine in turbot (Scophthalmus maximus) under production mode

摘要

Turbot (Scophthalmus maximus) is an important commercial fish in China, and Vibrio anguillarum is a common pathogen of turbot. Oil emulsified vaccines have been widely used to protect fish against V. anguillarum with long-term immune responses in several fish species. Side-effects, such as adhesions and growth reduction caused by oil-based adjuvants, however, limit the application of oil emulsions in turbot. In this study, turbot V. anguillarum serotype O1 and O2 bivalent inactivated vaccines were emulsified as water-in-oil (W/O) emulsions with four kinds of oil-based adjuvants: Freund's incomplete adjuvant (FIA), MOBIL (TM) Marcol 52 (Marcol 52), SEPPIC MontanideT ISA 763 A VG (ISA 763) and ISA 780 (ISA 780). Vaccine protection efficiency, fish adhesions, and growth were tested under production mode. The relative percent of survival (RPS) of W/O vaccines was all higher than that of the water-based (WB) vaccine at 7 days post vaccination. At 30 days post vaccination, the RPS of all vaccinated groups was over 90%, and most of the specific antibody titers of W/O vaccine-vaccinated fish were significantly higher than those of WB vaccines. Fish immunized with FIA, ISA 763, and ISA 780 adjuvants W/O vaccine showed serious tissue adhesions after vaccination, and their weight was significantly lower than control fish at 30 days post vaccination. Only slight or minor adhesions were observed in WB and Marcol 52 adjuvant vaccinated fish, which did not show growth reduction. These results indicate that Marcol 52 is a well-tolerated oil-based adjuvant for turbot, and could be used in vaccine development in further study.