Combating highly pathogenic avian influenza: Novel vaccination strategies using recombinant live avian viral vaccine vectors

抗击高致病性禽流感：使用重组活病毒疫苗载体的新疫苗接种策略。禽流感病毒(俗称“禽流感”)自然存在于水禽和岸鸟等野生禽鸟体内，这些禽鸟的病毒种类繁多，一般不具致病性。这些低致病性禽流感(LPAI)病毒通常从野鸟水库穿越而来，感染家禽，经常成为高致病性病毒(HPAI)，对商业家禽极其危险，偶尔会对人类造成致命影响。在包括欧盟在内的世界许多地区最近爆发的HPAI H5和H7亚型病毒疫情中，已有2亿多只家禽死亡或被扑杀，造成巨大的社会经济损失。目前的HPAI H5N1疫情源自东南亚，最近通过候鸟远距离传播，这是史无前例的。候鸟对英国和其他欧盟国家构成的风险大小尚不清楚，然而，越来越多的证据(最近苏格兰法夫市H5N1导致候天鹅死亡)表明，预防和控制家禽和其他圈养鸟类的禽流感疫情将是未来多年的主要挑战。迄今为止，在英国和其他一些国家，控制家禽HPAI的主要战略是通过大规模扑杀受感染的禽群和接触者群来根除病毒。然而，目前的世界性流行病严重影响了发达国家和发展中国家的经济。因此，出于伦理、生态和经济原因，主要通过大规模杀害动物来控制和根除人工智能不再被认为是可以接受的。因此，欧洲议会、世界动物卫生组织(OIE)和粮食及农业组织(FAO)不仅允许在疾病暴发后进行紧急疫苗接种，而且还允许预防性疫苗接种，作为控制禽流感的额外工具。目前，现有的禽流感灭活疫苗是用胚胎鸡蛋生产的，有几个缺点。我们建议使用一些最先进的生物技术工具来开发新型疫苗。这将允许在孵化时或蛋孵化前(在卵子接种中)作为单次注射接种活病毒疫苗。这些新的改良疫苗将是安全、有效和经济的，最重要的是保护商业家禽和其他家禽免受疾病和禽流感病毒向环境的传播，从而防止禽流感病毒的传播，避免迫在眉睫的全球大流行威胁。

Combating highly pathogenic avian influenza: Novel vaccination strategies using recombinant live avian viral vaccine vectors. Avian influenza (AI) viruses (or the 'avian flu' as it is commonly called) naturally exist in wild birds such as waterfowl and shore birds where the virus is highly diverse and generally not pathogenic. These low pathogenic avian influenza (LPAI) viruses routinely cross over from the wild-bird reservoir and infect domestic poultry, frequently becoming highly pathogenic viruses (HPAI), which are extremely dangerous to commercial poultry and are occasionally fatal to humans. In the recent outbreaks of HPAI viruses of H5 and H7 subtypes in many parts of the world, including the EU, more than 200 million domestic poultry have either died or been culled, impecting huge socio-economic costs. The current epidemic of HPAI H5N1 originating from south East Asia and recently transmitted over long distances via migratory birds is unprecedented. The magnitude of risk that migratory birds are posing to the United Kingdom and other EU countries is not clear, however, there is growing evidence (recent death of migratory swan by H5N1 in Fife, Scotland) suggesting that the prevention and control of AI disease outbreak in poultry and other captive birds will be a major challenge for many years to come. To date the main strategy for controlling HPAI in domestic poultry in UK and in some other countries has been eradication of the virus by large scale culling of infected and contact flocks. However, the current world-wide epidemic has severely affected the economies of developed as well as developing countries. Therefore, for ethical, ecological and economic reasons, it is no longer considered acceptable to control and eradicate AI mainly by the mass killing of animals. As a result the European Parliament, the World Organization for Animal Health (OIE) and Food and Agriculture Organization (FAO) have allowed not only emergency vaccination, following disease outbreak, but also preventive vaccination as an additional tools for the control of AI. Currently, the available AI inactivated vaccines are produced in embryonated eggs and have several disadvantages. We propose to develop novel vaccines using some of the state of the art biotechnological tools. These will allow the administration of live viral vaccines as single injection either at hatch or into eggs before they hatch (in ovo vaccination). These new improved vaccines will be safe, effective and economical, and above all protect the commercial poultry and other domestic birds from disease and dissemination of AI viruses into the environment, consequently preventing AI virus spread, averting the looming global pandemic threat.