Department of Aqualife Medicine, Chonnam National University, Yeosu, 550-749, Republic of Korea.
Vaccine. 2013 Apr 12;31(16):2025-7. doi: 10.1016/j.vaccine.2013.02.049. Epub 2013 Mar 7.
We investigated the long-term kinetics of nervous necrosis virus (NNV) infectivity in sevenband grouper, Epinephelus septemfasciatus, injected with a live NNV vaccine at 17.3°C and reared at natural seawater temperature. We also evaluated horizontal infection of NNV from fish vaccinated with live NNV to naïve fish in a cohabitation experiment. Although 10.5% mortality was observed in the vaccinated fish, they were strongly protected from the challenge with homologous NNV. The NNV infectivity titer was detected from day 5 after vaccination, peaked on day 10 at 10(7.43±0.35) TCID50/g, but NNV was under the detection limit (≤10(2.8) TCID50/g) between days 42 and 128. No mortalities or NNV were detected in any of the vaccinated and cohabitated naïve fish, suggesting that NNV spread from fish vaccinated with live NNV should be low if it is limited to fish in the late stage of vaccination (≥42 days from NNV inoculation). The present results demonstrate that a protective immune response to NNV was mounted in sevenband grouper by the live NNV vaccine without controlling fish rearing temperature.
我们研究了在 17.3°C 下注射活神经坏死病毒（NNV）疫苗并在天然海水温度下饲养的七带石斑鱼（Epinephelus septemfasciatus）中 NNV 感染力的长期动力学。我们还在共栖实验中评估了从接种活 NNV 的鱼向未接种的鱼的水平感染 NNV 的情况。尽管接种疫苗的鱼有 10.5%的死亡率，但它们受到同源 NNV 挑战的强烈保护。在接种疫苗后的第 5 天检测到 NNV 感染力滴度，在第 10 天达到峰值，为 10(7.43±0.35)TCID50/g，但在第 42 天至第 128 天之间，NNV 检测不到（≤10(2.8)TCID50/g）。在接种疫苗和共栖的未接种鱼中均未检测到死亡或 NNV，这表明如果仅限于接种后的晚期鱼类（从 NNV 接种后≥42 天），活 NNV 疫苗传播的 NNV 应该很低。本研究结果表明，在不控制鱼类养殖温度的情况下，活 NNV 疫苗可在七带石斑鱼体内引发针对 NNV 的保护性免疫反应。
