Survival of vaccinated, feed-trained largemouth bass fry (Micropterus salmoides floridanus) during natural exposure to Flavobacterium columnare

Vaccinated, feed-trained largemouth bass fry (Micropterus salmoides floridanus) were cohabited with sham-vaccinated fish. Fish were exposed, under natural conditions, to Flavobacterium columnare, a ubiquitous bacterium associated with columnaris disease. During every time interval, the probability that a vaccinated fish would survive past time, t, was greater than for sham-vaccinated fish and survivor functions were significantly different (p-value <0.001). Overall, vaccinated fish had a 43% lower risk of death during the field trial. Overall incidence was 1.7 times greater for the sham-vaccinated (1.4%/d) as compared to the vaccinated fish (0.8%/d). Vaccination with AQUAVAC-COL (Intervet/Schering-Plough Animal Health) significantly reduced the risk of death from columnaris disease in feed-trained largemouth bass fry.