Submitted to: Veterinary Immunology International Symposium
Publication Type: Other
Publication Acceptance Date: June 30, 2001
Publication Date: July 15, 2001
Citation: SHOEMAKER, C.A., KLESIUS, P.H., EVANS, J.J. IN OVO VACCINATION OF CHANNEL CATFISH. VETERINARY IMMUNOLOGY INTERNATIONAL SYMPOSIUM. POSTER. 2001. Technical Abstract: Eyed channel catfish (Ictalurus punctatus) eggs were vaccinated by immersion exposure with a modified live Edwardsiella ictaluri vaccine. In ovo experiments were carried out in two trials where eyed eggs were either immunized singly and/or singly with booster. Fry from immunized and non-immunized eggs were challenged with virulent E. ictaluri at either 33 (trial 1) or 60 (trial 2) days post immunization. Relative percent survival of single immunized fry was 87.9 in trial 1, however, data did not fit Amend=s criteria of 60% mortality in the non-immunized fish. In trial 2, mean percent mortality in the non-immunized fry (64.2+5.8) was significantly higher (p=0.003) than mean percent mortality in the fry immunized singly as eggs or fry that received a booster immunization (25.8+5.1 and 46.7+0.8, respectively). Relative percentage survival was 59.7 in the single immunized fry and 27.3 in the booster immunized fry. The resulting low RPS from the fry twice immunized (trial 2 only) suggests that tolerance may have occurred possibly due to presence of excess antigen in relation to antigen presenting cells as suggested in other animals. Results of single immunization of eyed fish eggs indicates that in ovo vaccination is possible. Successful in ovo vaccination of fish eggs will allow for the earliest immunization of fish (i.e., in the hatchery).