Vaccination programmes in aquaculture prevent disease and reduce antibiotic use, delivering significant welfare benefits across farmed fish populations.
Fish vaccination involves a welfare trade-off: the acute pain of injection and post-injection inflammation must be weighed against the significant welfare benefit of disease prevention. Without vaccination, bacterial disease outbreaks cause mass mortality and suffering in farmed fish. The net welfare benefit of vaccination programmes is substantial. Improving vaccine delivery through better formulations that reduce post-injection reactions, and refinement of injection techniques to minimise tissue damage, are important ongoing welfare goals for the aquaculture industry.