Viral encephalopathy and retinopathy (VER), caused by nervous necrosis virus (NNV), is one of the most
threatening diseases affecting marine farmed fish, especially in early developmental stages. In addition, subclinical
infections are commonly detected in both farmed and wild fish. In recent years numerous efforts have
been made to achieve effective vaccines for the protection of different fish species against NNV infection.
Vaccination experiments are always conducted on pathogen-free animals, but subclinically infected individuals
may respond differently to immunization. In this study, we have observed a different response between
experimentally-induced-NNV carrier Senegalese sole and NNV-free animals when immunized with a BEIinactivated
vaccine, whereas mock-vaccinated carrier fish behaved like the NNV-free group.
