Institute of Aquaculture, University of Stirling, Stirling, UK.
Chonnam National University, Yeosu, Republic of Korea.
Fish Shellfish Immunol. 2019 Feb;85:44-51. doi: 10.1016/j.fsi.2017.10.005. Epub 2017 Oct 7.
Flavobacterium psychrophilum is the causative agent of Rainbow Trout Fry Syndrome which has had a major impact on global salmonid aquaculture. Recent outbreaks in Atlantic salmon in Scotland and Chile have added to the need for a vaccine to protect both salmon and trout. At present no licensed vaccines are available in Europe, leaving antibiotics as the only course of action to contain disease outbreaks. Outbreaks generally occur in fry at temperatures between 10 and 15 °C. Recently outbreaks in larger fish have given added impetus to the development of a vaccine which can provide long term protection from this highly heterogeneous pathogen. Most fish injectable vaccines are formulated with oil emulsion adjuvants to induce strong and long lasting immunity, but which are known to cause side effects. Alternative adjuvants are currently sought to minimise these adverse effects. The current study was performed to assess the efficacy of a polyvalent, whole cell vaccine containing formalin-inactivated F. psychrophilum to induce protective immunity in Atlantic salmon. The vaccine was formulated with an adjuvant containing squalene and aluminium hydroxide, and was compared to a vaccine formulated with a traditional oil adjuvant, Montanide ISA 760VG, and a non-adjuvanted vaccine. Duplicate groups of salmon (23.5 ± 6.8 g) were vaccinated with each of the vaccine formulations or phosphate buffered saline by intraperitoneal injection. Fish were challenged by intramuscular injection with F. psychrophilum six weeks post-vaccination to test the efficacy of the vaccines. Cumulative mortality reached 70% in the control salmon, while the groups of salmon that received vaccine had significantly lower mortality than the controls (p = 0.0001), with no significant difference in survival between vaccinated groups. The squalene/alum adjuvant was safe, more readily metabolised by the fish and induced less histopathological changes than the traditional oil adjuvant.
嗜冷杆菌是彩虹鳟鱼苗综合征的病原体，这种疾病对全球鲑鱼养殖业造成了重大影响。苏格兰和智利最近爆发的大西洋鲑鱼疫情加剧了对疫苗的需求，以保护鲑鱼和鳟鱼。目前，欧洲没有许可的疫苗，抗生素是控制疾病爆发的唯一手段。疫情通常发生在 10 至 15°C 的鱼苗中。最近，较大鱼类的疫情促使人们开发一种疫苗，为这种高度异质的病原体提供长期保护。大多数鱼类注射用疫苗都使用油乳剂佐剂来诱导强烈和持久的免疫力，但众所周知，这些佐剂会引起副作用。目前正在寻找替代佐剂来尽量减少这些不良反应。本研究旨在评估一种含有福尔马林灭活嗜冷杆菌的多价全细胞疫苗在诱导大西洋鲑鱼保护性免疫中的功效。该疫苗的佐剂含有角鲨烯和氢氧化铝，并与含有传统油佐剂 Montanide ISA 760VG 的疫苗和非佐剂疫苗进行了比较。两组（23.5±6.8g）鲑鱼通过腹腔注射分别接种了每种疫苗制剂或磷酸盐缓冲盐水。在疫苗接种后六周，通过肌肉内注射嗜冷杆菌对鲑鱼进行攻毒，以测试疫苗的功效。对照组鲑鱼的累积死亡率达到 70%，而接种疫苗的鲑鱼组的死亡率明显低于对照组（p=0.0001），接种组之间的存活率无显著差异。角鲨烯/明矾佐剂是安全的，更易于被鱼类代谢，引起的组织病理学变化也少于传统油佐剂。
