title: Effect of booster shot and investigation of vaccination efficacy period against herpesviral haematopoietic necrosis (HVHN) in goldfish Carassius auratus.
abstract: In this study, the efficacy period of an intraperitoneal vaccination and effect of a booster shot of vaccine against herpesviral haematopoietic necrosis (HVHN) in goldfish Carassius auratus were investigated. Cell culture supernatant of cyprinid herpesvirus 2 (CyHV-2), causative agent of HVHN, propagated in goldfish fin (GFF) cells was inactivated with formalin (0.1%, v/v) for 2 days at 4 °C. Three groups of the variety Ryukin were individually intraperitoneally injected with the vaccine and each group was separately maintained in replicate tanks. After 4 weeks (Vaccinated-4w-1 and 2) and 8 weeks (Vaccinated-8w-1 and 2) from the first vaccination, the fish were CyHV-2-challenged by the immersion route (10 TCID50 l(-1)). In addition, the other vaccinated group of fish were injected with a booster vaccine 4 weeks after the first vaccination as the Vaccinated-booster groups, then the fish of these groups were CyHV-2-challenged by the immersion route (10 TCID50 l(-1)) after 8 weeks from the first vaccination. The mean of the relative percentage survival (RPS) values of the Vaccinated-4w and 8w groups showed 42.5% and 57.6%, respectively. In addition, the mean RPS value of Vaccinated-booster groups showed 63.6%. Statistical analysis showed significantly higher survival rates in all the vaccinated groups than those of the respective negative control groups using Fisher's exact test. Moreover, the survival rates of vaccinated-booster groups were significantly higher (p=0.036) compared with the respective control groups by Student's t test. The present study shows the efficacy period of the vaccine is at least 8 weeks and a booster shot showed a tendency to enhance the protection against HVHN in goldfish.
authors.affiliation: Tamaki Laboratory, Aquatic Animal Health Division, National Research Institute of Aquaculture, Fisheries Research Agency, 224-1 Hiruda, Tamaki, Mie 519-0423, Japan. Electronic address: takafumi@fra.affrc.go.jp.
authors.forename: Takafumi
authors.initials: T
authors.lastname: Ito
authors.affiliation: Aquatic Animal Health Division, National Research Institute of Aquaculture, Fisheries Research Agency, 422-1 Nakatsuhamaura, Minami-Ise, Mie 516-0193, Japan.
authors.forename: Yukio
authors.initials: Y
authors.lastname: Maeno
mesh_terms: D000818:Animals; D002460:Cell Line; D004279:DNA, Viral / Q000235:genetics; D005393:Fish Diseases / Q000517:prevention & control* / Q000821:virology; D006054:Goldfish; D006564:Herpesviridae / Q000235:genetics / Q000276:immunology*; D006566:Herpesviridae Infections / Q000517:prevention & control / Q000662:veterinary* / Q000821:virology; D007117:Immunization, Secondary / Q000662:veterinary; D009336:Necrosis / Q000517:prevention & control* / Q000662:veterinary; D014611:Vaccination / Q000662:veterinary*; D014765:Viral Vaccines / Q000008:administration & dosage* / Q000276:immunology
chemical_list: D004279:DNA, Viral; D014765:Viral Vaccines
keywords: Cyprinid herpesvirus 2; Fish viral disease; Goldfish; Herpesviral haematopoietic necrosis; Vaccination