Vaccine Efficacy of a Newly Developed Feed-Based Whole-Cell Polyvalent Vaccine against Vibriosis, Streptococcosis and Motile Aeromonad Septicemia in Asian Seabass, Lates calcarifer

Multiple infections of several bacterial species are often observed under natural farm conditions. The would cause a much more significant loss compared to single infectious agent. Vaccination is an essential strategy prevent diseases in aquaculture, and oral vaccination has been proposed as promising technique since it requires no handling the fish easy perform. This research attempts develop evaluate potential feed-based polyvalent vaccine that can be used treat multiple by Vibrios spp., Streptococcus agalactiae, Aeromonas hydrophila, simultaneously. was prepared mixing formalin-killed V. harveyi, S. A. hydrophila strains with commercial feed pellet, palm oil adjuvant added improve their antigenicity. Thereafter, vaccinated pellet tested for quality analysis terms stability water, proximate nutrient analysis, palatability, safety, growth performance using Asian seabass, Lates calcarifer host model. For immune response total 300 seabass juveniles (15.8 ± 2.6 g) were divided into two groups triplicate. Fish group 1 not vaccinated, while 2 vaccine. Vaccinations carried out on days 0 14 administration containing bacterin at 5% body weight. Samples serum antibody lysozyme study spleen gut gene expression collected 7-day intervals 6 weeks. Its efficacy protecting evaluated aquarium challenge. Following vaccine, IgM levels showed (p < 0.05) increase against Vibrio agalactiae reached peak week 3, 5, 6, respectively. high-stimulated remained significantly higher than control end weeks trial. Not only that, but level also increased 4 treatment. immune-related gene, dendritic cells, C3, Chemokine ligand (CCL4), major histocompatibility complex class I (MHC I) after In challenge, provided relative percentage survival 75 7.1%, 80 0.0%, 0.0% challenge Combining our results demonstrate could elicit innate adaptive immunological responses, this offers opportunity comprehensive immunization vibriosis, streptococcosis, motile aeromonad septicemia calcarifer. Nevertheless, newly developed effective large-scale aquaculture industry shortly.