Nodavac-R

• Viral nervous necrosis (VNN) or viral encephalopathy and retinopathy (VER) is an acute viral disease of several fish species causing up to 100% mortality in larval and early juvenile stages. Adult fish when infected, is asymptomatic, but can transmit the virus to the offspring through eggs and gonadal fluids.
• The disease is caused by an RNA virus, Red-spotted nervous necrosis virus (RGNNV) belonging to the genus Betanodavirus.
• Diagnosis
  • Clinical signs: Erratic swimming, hyperinflation of swim bladder, belly up, skin darkening
  • Histology: Vacuolation in brain and retina
  • Virus Detection: RT-PCR, qPCR, ELISA
• Vaccination is the practical strategy to build immunity and prevent vertical transmission of NNV.
• Nodavac-R is a recombinant vaccine against VNN caused by RGNNV. The vaccine consists of recombinant capsid protein of RGNNV expressed in Escherichia coli. The purified recombinant capsid protein is emulsified with adjuvant.
• The vaccine can be used to prevent VNN in fingerling and adult finfish of all susceptible species and to prevent vertical transmission of the virus from brooders to offspring.
• The vaccine can be administered intraperitoneally to fingerlings and brooders on the midline posterior to the pelvic fin.
• Dose: 0.1 ml/fish weighing >20 g and 0.5 ml for brooders intraperitoneally.
• Onset of immunity is 2 weeks post immunization. The vaccine reduces mortality up to 6 months post-vaccination. Larvae produced by vaccinated brooders are free of virus and possess maternal antibodies against RGNNV.