Duration of protective immunity and antibody titres measured by ELISA after vaccination of rainbow trout, Salmo gairdneri Richardson, against vibriosis

Abstract

. The level of protective immunity in rainbow trout, Salmo gairdneri Richardson, following vaccination by intraperitoneal (i.p.) injection or by direct immersion with Vibrio anguillarum was studied over a period of 46 weeks. Antibody titres to V. anguillarum O‐antigen were determined with ELISA at the time of each experimental infection to study the relation between specific antibody production and protective immunity. Both vaccination by i.p. injection and vaccination by direct immersion induced a high degree of protective immunity against vibriosis which lasted for at least 46 weeks. At each experimental infection, the proportions of seropositive fish were lower than the proportions of fish with protective immunity. However, seropositive individuals were found in both experimental groups throughout the study.

Temperature effect on the immune defense functions of Arctic charr Salvelinus alpinus

“…The specific antibody response towards aAS (but not tAS) was analyzed because the amount of plasma was limited and the response towards aAS was considered more important. Anti-aAS-specific antibodies were analyzed with a double-sandwich enzyme-linked immunosorbent assay (ds-ELISA) with 1% (w/v) bovine serum albumin (BSA) in phosphatebuffered saline (PBS) as the blocking solution (Thuvander et al 1987, Magna7ottir & Gudmunds7ottir 1992 in wells precoated with poly-L-lysine (Graves 1988). Microplates were coated with 10 -5 cfu ml -1 of sonicated aAS cells (Sorensen & Brodbeck 1986, Kuen et al 1993).…”

“…Antibody responses after active immunization have been studied in Atlantic salmon Salmo salar, brown trout Salmo trutta, and various Oncorhynchus species (Thuvander et al 1987, Gudmunds7ottir & Magna7ottir 1997. Humoral antibodies and neutralization of bacterial toxins are important protective mechanisms in fishes (Gudmunds7ottir & Magna7ottir 1997).…”

“…Vaccination against furunculosis and vibriosis (Vibrio anguillarum) is a well-established practice in fish farming, and has also been successful in protecting brown trout Salmo trutta m. lacustris, Atlantic salmon, and rainbow trout Oncorhynchus mykiss (Thuvander et al 1987, 1993, Midtlyng et al 1996. Arctic charr vaccinated with commercial, monovalent or multivalent furunculosis vaccines shave, nevertheless, been diagnosed as having died due to aAS infection (Pylkkö unpubl.…”

Route of vaccine administration:effects on the specific humoral response in rainbow trout Oncorhynchus mykiss

“…With Vibno anguillarum, the protective role of antibody has been demonstrated following injection vaccination (Thuvander et al 1987) and passive immunization (Harrell et al 1975). However, the correlation has not always been clear after immersion vaccination, and most studies on oral vaccination against vibriosis have shown no correlation (Smith 1988, Quentel & Vigneulle 1997.…”

“…However, the correlation has not always been clear after immersion vaccination, and most studies on oral vaccination against vibriosis have shown no correlation (Smith 1988, Quentel & Vigneulle 1997. Thuvander et al (1987) concluded that the importance of low levels of antibodies is unclear, but that the presence of specific antibodies in a proportion of the fish after vaccination seems to indicate that the whole population is protected. This appears to be the case in the current study, where low ELISA titers in immersion vaccinates before boosting (Fig.…”