State Key Laboratory of Freshwater Ecology and Biotechnology of Hydrobiology Academy of Sciences;
Department of Aquatic Animal Medicine of Fisheries Agricultural University;
Wuhan Chopper Fishery Bio-Tech Co. Academy of Agricultural Science;
Mucosal immune response; Bivalent inactivated vaccine; Immersion vaccination; Aeromonas veronii; Edwardsiella ictaluri; Yellow catfish;