Acquired protection in Atlantic salmon Salmo salar parr and post-smolts against pancreas disease

Experimental infection of Atlantic salmon Salrno salar parr and post-smolts with pancreas disease infective kidney homogenate induced a highly significant protection against the disease following exposure to challenge infections at either 3 , 4 , 7 or 9 mo after the initial infection.Protection was maintamed in fish infected as parr and exposed to a challenge infection following smolting and sea water transfer.A carrier status was not demonstrated in immune fish since homogenates of kidneys taken 1 and 2 wk post-challenge were not infective, unlike homogenates of kidneys from non-immune fish.