Birnagen Forte As Uses For active immunisation against Aeromonas salmonicida and Infectious Pancreatic Necrosis Virus (IPNV) to reduce furunculosis and IPNV related mortality of Atlantic salmon populations. Onset immunity for A.salmonicida occurs within 430 degree days following vaccination. Onset of immunity for IPNV occurs within 817 degree days following vaccination. Duration of immunity for A.salmonicida and IPNV is unknown. Efficacy has not been fully evaluated.