Development of a vaccine against avian reovirus infection in broiler chickens

禽呼肠孤病毒（Avian reoviruses，ARV）是一种具有重要经济意义的新型禽类疾病的病原体，由关节源性ARV引起的腱鞘炎/关节炎综合征（Tenosynovitis/arthritis syndrome，TS）是以单侧或双侧跗关节肿胀导致跛行为特征的疾病。根据严重程度，ARV感染导致生长不良和生产不良，有时甚至死亡，给家禽业造成相当大的经济损失。虽然商业疫苗是可用的，新出现的强毒株的ARV，继续影响加拿大家禽业的发病率表明，目前的疫苗是不有效的对流通的ARV株。疫苗接种是保护肉鸡免受ARV感染的首选手段，目前加拿大一些农场使用自体疫苗预防鸡的ARV感染，但自体疫苗诱导的免疫力不可预测，作为ARV专用控制措施的潜力有限。没有有效的疫苗可用于对抗目前在加拿大肉鸡产业中流行的新出现的ARV毒株。如果抗逆转录病毒药物继续引起疾病，加拿大肉鸡业将继续遭受重大经济损失。因此，根据ARV流行毒株的特性，研制安全、有效的ARV疫苗是十分必要的。我们已经在遗传和免疫学水平上对萨斯喀彻温省肉鸡产业中出现的变异抗逆转录病毒进行了特征化。我们已经证明，四种基因型的ARV影响萨斯喀彻温省肉鸡产业，这些基因型不能控制的ARV疫苗只包含一个类型。我们建议开发一种安全有效的抗ARV多价活疫苗和灭活疫苗，专门为加拿大家禽业量身定制，以控制新出现的ARV感染。

Avian reoviruses (ARVs) are etiological agents for an economically important emerging poultry disease.Arthrogenic ARVs cause tenosynovitis/arthritis syndrome which is characterized by unilateral or bilateralswelling of the hock joint resulting in lameness. Depending on the severity, ARV infection results in poorgrowth and poor production, and sometimes death, causing considerable economic losses to the poultryindustry. While commercial vaccines are available, the incidence of emerging virulent strains of ARV thatcontinue to impact the Canadian poultry industry suggest that current vaccines are not effective againstcirculating ARV strains. Vaccination is the preferred means to protect broiler chickens from ARV infection.Currently, some farms in Canada use autogenous vaccines to prevent ARV infection in chickens; however,autogenous vaccines induce unpredictable immunity and have limited potential as a dedicated control measureagainst ARVs. There is no effective vaccine available against the emerging ARV strains currently circulating inthe Canadian broiler chicken industry. If ARVs continue to cause disease, the Canadian broiler chickenindustry will continue to suffer significant economic losses. Therefore, the development of a safe and aneffective vaccine based on the characteristics of circulating virulent strains of ARV is essential. We havecharacterized emerging variant ARVs from the broiler chicken industry in Saskatchewan at the genetic andimmunological level. We have demonstrated that four genotypes of ARV affect the Saskatchewan broilerchicken industry and these genotypes cannot be controlled by a ARV vaccine containing just one type. Wepropose to develop a safe and effective multivalent live and inactivated vaccine against ARVs specificallytailored for the Canadian poultry industry to control emerging ARV infections.