Department of Aqualife Medicine, Chonnam National University, Yeosu, Republic of Korea; Gyengsangbuk-do Fishery Technology Center, Pohang, Republic of Korea.
Department of Aqualife Medicine, Chonnam National University, Yeosu, Republic of Korea; Aquatic Disease Control Division, National Institute of Fisheries Science (NIFS), Busan, Republic of Korea.
Virus Res. 2021 Jan 15;292:198227. doi: 10.1016/j.virusres.2020.198227. Epub 2020 Nov 10.
The objective of this study was to investigate safety and efficacy using a low-temperature immunization protocol with NNV in sevenband grouper, Epinephelus septemfasciatus. Further, NNV specific antibody post immunization and intramuscularly challenge was also evaluated. Immunization at low temperature resulted in a low titer virus infection in brain tissues without any clinical symptoms of infection such as sluggish behavior and/or spinning, rotating swimming being observed, and no mortality was observed. Post challenge, NNV titer NNV giving an RPS of 100 %, increased in brain tissues of naïve (non-immunized) sevenband grouper NNV giving an RPS of 100 %, with a cumulative mortality of 100 % at 25 days post-infection. No mortality or disease symptoms NNV giving an RPS of 100 %, as NNV giving and of 100 %, observed in the groups immunized at low temperature with live NNV giving an RPS of 100 %. NNV giving an RPS of 100 %. NNV specific antibody was not detected in live NNV vaccinated sevenband grouper. This is the first study that confirms that field-scale NNV immersion vaccine can protect sevenband grouper against lethal infection with NNV at natural seawater temperature under the gradually increased from 14.3-24.8 °C.
本研究旨在探讨七带石斑鱼（Epinephelus septemfasciatus）采用低温免疫方案接种神经坏死病毒（NNV）的安全性和有效性。此外，还评估了免疫后及肌肉内攻毒时的 NNV 特异性抗体。低温免疫导致脑组织中出现低滴度病毒感染，但未观察到感染的临床症状，如行为迟缓或旋转游泳，也未观察到死亡率。攻毒后，未免疫的七带石斑鱼脑组织中的 NNV 滴度增加，RPS 为 100%，25 天感染后累积死亡率为 100%。在低温下用活 NNV 免疫的鱼群中未观察到死亡率或疾病症状，RPS 为 100%，而在接受活 NNV 疫苗接种的鱼群中未检测到 NNV 特异性抗体。这是首次证实，在自然海水温度下（逐渐从 14.3-24.8°C 升高），现场规模的 NNV 浸泡疫苗可以保护七带石斑鱼免受 NNV 的致死性感染。
