A Systematic Approach towards Optimizing a Cohabitation Challenge Model for Infectious Pancreatic Necrosis Virus in Atlantic Salmon (Salmo salar L.)

• Published in: PloS one 2016-02, Vol.11 (2), p.e0148467-e0148467
• Main Authors: Munang'andu, Hetron Mweemba, Santi, Nina, Fredriksen, Børge Nilsen, Løkling, Knut-Egil, Evensen, Øystein
• Format: Article
• Language: English
• Subjects: Animals; Aquaculture; Biology and Life Sciences; Birnaviridae Infections - veterinary; Causes of; Cohabitation; Disease Susceptibility; Diseases and pests; Dosage; Effectiveness; Fish; Fish Diseases - mortality; Fish Diseases - prevention & control; Fish Diseases - virology; Immunization; Infectious diseases; Infectious pancreatic necrosis; Infectious pancreatic necrosis virus - classification; Infectious pancreatic necrosis virus - genetics; Infectious pancreatic necrosis virus - immunology; Mathematical models; Medicine and Health Sciences; Models, Theoretical; Mortality; Necrosis; Oncorhynchus mykiss; Optimization; Pancreas; Physical Sciences; Physiological aspects; Prevention; Regression models; Reproducibility; Reproducibility of Results; Research and Analysis Methods; Salmo salar; Salmo salar - immunology; Salmo salar - virology; Salmon; Salmonidae; Studies; Trout; Vaccine efficacy; Vaccines; Viral vaccines; Viral Vaccines - administration & dosage; Viral Vaccines - immunology; Virus Shedding; Viruses
• ISSN: 1932-6203; 1932-6203
• DOI: 10.1371/journal.pone.0148467

A cohabitation challenge model was developed for use in evaluating the efficacy of vaccines developed against infectious pancreatic necrosis virus (IPNV) in Atlantic salmon (Salmo salar L) using a stepwise approach. The study involved identifying a set of input variables that were optimized before inclusion in the model. Input variables identified included the highly virulent Norwegian Sp strain NVI015-TA encoding the T217A221 motif having the ability to cause >90% mortality and a hazard risk ratio of 490.18 (p75% in the unvaccinated fish in order to attain a high discriminatory capacity (DC) between the vaccinated and control fish as a measure of vaccine efficacy. The model shows the importance of using highly susceptible fish to IPNV in the optimization of challenge models by showing that highly susceptible fish had a better DC of differentiating vaccine protected fish from the unvaccinated control fish than the less susceptible fish. Once all input variables were optimized, the model was tested for its reproducibility by generating similar results from three independent cohabitation challenge trials using the same input variables. Overall, data presented here show that the cohabitation challenge model developed in this study is reproducible and that it can reliably be used to evaluate the efficacy of vaccines developed against IPNV in Atlantic salmon. We envision that the approach used here will open new avenues for developing optimal challenge models for use in evaluating the efficacy of different vaccines used in aquaculture.