Farmed Salmon Vaccination: Reducing Antibiotic Use and Improving Welfare

Vaccination of farmed salmon has been one of the greatest successes in aquaculture welfare and sustainability. Norwegian salmon farming reduced antibiotic use by over 99% following vaccination adoption.

Key Facts

Norway reduced antibiotic use in salmon farming from 50 tonnes in 1987 to under 1 tonne today
Furunculosis vaccines introduced in the early 1990s drove this transformation
Current multivalent vaccines protect against vibriosis, furunculosis, and IHN
Vaccination is performed by injection under sedation - welfare implications are of increasing concern
Vaccine reactions (peritoneal adhesions) are a recognised welfare issue in some formulations
Oral and immersion vaccine delivery routes are under development to reduce injection stress

Welfare Considerations

The reduction of antibiotic use through vaccination is a significant welfare advance - fish that do not develop bacterial disease avoid the suffering of infection. However, the vaccination process itself has welfare implications. Injection requires sedation and physical handling, causing stress. Intraperitoneal injection can cause peritoneal inflammation and adhesions in some formulations. Advances in vaccination routes that reduce handling stress while maintaining protection are an active welfare research priority.

What You Can Do

Support regulatory frameworks requiring vaccination programmes in salmon farming
Ask retailers about antibiotic use and vaccination rates in their salmon supply chains
Encourage research into injection-free vaccination delivery methods
Advocate for welfare assessment of vaccination procedures in certification schemes
Contribute to research evaluating welfare outcomes of different vaccine formulations