The Efficacy of Inactivated Virus Vaccine against Viral Nervous Necrosis (VNN)

ウイルス性神経壊死症に対する不活化ワクチンの有効性

Yamashita Hirofumi

Fujita Yoshiyuki

Kawakami Hidemasa

Nakai Toshihiro

魚病研究

Fish Pathology

ホルマリンで不活化したベータノダウイルスのワクチンとしての有効性をマハタ稚魚を用いて調べた。不活化ウイルスを腹腔内接種すると10日後からウイルス中和抗体が検出され、免疫後21～77日の間、平均1 : 2000以上の高い抗体価で推移した。抗体価はその後低下したが160日後でも抗体保有魚が認められた。免疫14、35および74日目にワクチン株による注射攻撃試験を行った結果、ワクチン接種区は対照区に比べていずれも有意に高い生残率を示した(RPS=67～100)。また、野外での自然感染に対しても高いワクチン効果が認められた(RPS=85)。

The efficacy of inactivated betanodavirus as a vaccine against viral nervous necrosis (VNN) was evaluated using juvenile sevenband grouper Epinephelus septemfasciatus. Fish were intraperitoneally injected once with formalin-inactivated redspotted grouper nervous necrosis virus (RGNNV). Virus-neutralizing antibodies were detected in the vaccinated fish from Day 10 to the end of the experimental period (Day 160), showing 1: 2,000 or higher mean antibody titers from Day 21 to Day 77. The vaccinated and unvaccinated control fish were challenged by intramuscular injection with the homologous virus at 14, 35 and 74 days post-vaccination. The vaccinated fish showed significantly lower mortalities at any challenges than the control fish, with the RPS (relative percent survival) values 67 or higher. A field trial, in which fish were exposed to natural infection in net pens, also resulted in higher survival rates in the vaccinated fish (RPS = 85) during the experimental period of 9 weeks. This high induction of neutralizing antibodies and protection indicates the potential of the inactivated virus vaccine against VNN.

betanodavirus

viral nervous necrosis

viral encephalopathy and retinopathy

vaccination

Epinephelus septemfasciatus

inactivated vaccine

VNN

VER

Fishing industry. Fisheries [ 660 ]

eng

日本魚病学会

Copyright (c) 2005 The Japanese Society of Fish Pathology

[ISSN] 0388-788X

[NCID] AN00063165