Over half of the salmon consumed globally are farm-raised, and in most cases are given vaccines. The vaccines make large-scale production feasible by preventing infections.
Currently, the vaccines used contain oil adjuvants, such as mineral oil. In rodents, a single injection of adjuvant hydrocarbon oil induces lupus-like systemic autoimmune syndrome, characterized by autoantibodies, immune complex glomerulonephritis, and arthritis.
A study attempted to find out if farmed salmon that received oil-adjuvanted vaccine developed similar autoimmune syndromes. Sera and tissues were collected from vaccinated or unvaccinated farmed salmon and wild salmon.
The researchers found that autoimmune disorders similar to those seen in the mouse model were common in vaccinated farmed Atlantic salmon. This could have a significant impact on production loss, disease of previously unknown etiology, and future strategies of vaccines and salmon farming.