Amoebic gill disease (AGD) is the main disease affecting salmonids in Tasmania, Australia. The aetiological agent is Neoparamoeba perurans and the clinical presentation produces severe mortalities if left untreated. The current treatment (fresh water bathing) decreases the number of amoebae on the gills, but it is costly for the industry. The development of a vaccine remains a high priority.

Previous work identified a Mannose binding– like protein (MBL) in N. perurans, similar to attachment factors of other amoebae, suggesting that by interfering with MBL and blocking attachment of N. perurans, the severity of AGD could be reduced. Before subjecting the fish to this vaccine candidate, it would be important to know the ability of Atlantic salmon in generating a mucosal immune response. The administration of an antigen with known immunogenicity would allow a proper evaluation of vaccination and sampling procedures.

Atlantic salmon were immunized with two different protein-hapten antigens: fluorescein isothiocyanate and dinitrophenol, both coupled with keyhole limpet haemocyanin. A number of exposure routes were tested, and both systemic and mucosal antibody responses were measured using ELISA for a period of 10 weeks. This will identify the best method of immunization for production of specific antibodies in the mucus.