Autogenous vaccines in aquaculture: Tool to combat resistance of bacteria to antibiotics?

New technological progress and increased demands for fish as a source of animal protein are driving significant growth of aquaculture production. Intensification of production increases the severity and frequency of infectious disease outbreaks, and so requires significant effort to prevent and control disease. Because of the global crisis of bacterial resistance to antibiotics, the use of antibiotics in aquaculture is increasingly subjected to strict control and regulatory measures, leading to potential misuse. The lack of availability of approved veterinary medical products for use in aquaculture, combined with the risk of drug resistance development and antibiotic residues in fish flesh or water, support the development of preventive actions, including vaccines. However, the diversity of species and aquaculture production methods, including epidemiological units and their links, results in economic challenges for commercial vaccine development and authorization. As a possible response to the increasing demand for less antibiotic use in fish farms, and to the expenses associated with novel veterinary product development, there is a need for increased use of safe and effective autogenous vaccines in aquaculture. Regulatory processes for autogenous vaccine production, approval and application should recognize the specificities of epidemiological units and their links in aquatic animal production facilities. The joint efforts of regulatory authorities, producers, and veterinary services to follow veterinary biosecurity principles, including risk analysis, surveillance, and selection/prioritization of pathogens, are essential to provide maximum safety and efficacy of autogenous vaccines as disease prevention and control tools within larger areas, such as compartments and zones, and allow for reductions in antibiotic use.