Vaccination has dramatically reduced antibiotic use in Norwegian salmon farming and improved fish welfare by preventing disease. Advances in vaccine technology continue to improve efficacy and welfare outcomes.
Vaccination represents one of the most significant welfare improvements in salmon aquaculture, preventing disease outbreaks that cause mass suffering and death. The welfare cost of injection vaccination - acute stress from individual handling - is far outweighed by the welfare benefit of disease prevention. Developing more effective immersion or oral vaccines would further reduce this welfare trade-off.