Experimental biofilm vaccines for fish aquaculture: an overview

Biofilm vaccines in fish are a trending approach to fighting bacterial diseases. Pathogens, including Aeromonas spp., Vibrio spp., Photobacterium spp., and Streptococcus spp., have been studied for planktonic- and biofilm-derived vaccines. These vaccines have demonstrated safe immunogenicity through the induction of phagocytosis, innate-immune related gene expression, and specific antibodies. Remarkably, protective outcomes range from 77 to 100% in several fish species upon challenges by disrupting biofilm formation, compared to planktonic-derived vaccines that have reached around 30% protection. Oral immunization is the most investigated and desirable route, although other routes have been explored. A comprehensive review of the state-of-the-art biofilm-based vaccines is described, including mechanisms of biofilm formation, biofilm-derived antigens, and strategies for their evaluation, providing experimental results along with benefits, obstacles, and perspectives for their affordable use in fish aquaculture.