Prevention of Inclusion Body Hepatitis (IBH) in the broiler Chicken Industry: Optimizing Two Prototype Fowl Adenoviral Vaccines

包涵体肝炎(IBH)是鸡的一种急性病毒性疾病，其特征是突然发病，病死率高，肝组织严重坏死，核内可见包涵体。IBH由几种不同血清型的禽腺病毒(FAdV)引起。自2000年以来，IBH已成为加拿大肉鸡养殖业的头号经济重要疾病。尽管萨斯喀彻温省只占加拿大肉鸡行业销售额的4%，但由于IBH死亡，该省每年损失超过30万美元。因此，加拿大肉鸡业的总生产力损失要高得多，估计为数百万美元。我们能够确定加拿大IBH的暴发主要是由于父母垂直传播FAdv所致。我们还证明了五种主要的FAdV血清型会在加拿大引起IBH，通过给肉鸡育种者接种灭活或活FAdV疫苗，可以显著保护肉鸡免受IBH的侵袭。虽然，在工业界和NSERC的财政支持下，我们能够生产出两种针对IBH的原型疫苗，但我们需要优化这些灭活和活的FAdV疫苗，以提高它们的效力，然后才能制造它们，并将其投入加拿大肉鸡业的商业应用。这项研究将优化FAdV活疫苗和灭活FAdV疫苗，并在分子水平上加深我们对FAdV脱落和突变变化的理解。

Inclusion body hepatitis (IBH) is an acute viral disease in chickens characterized by sudden onset of high mortality with severe hepatic necrosis with microscopic intranuclear inclusion bodies. IBH is caused by several different serotypes of fowl adenoviruses (FAdV). Since 2000, IBH has emerged as the number one economically important disease for the broiler chicken industry in Canada. Although Saskatchewan has only 4% of the Canadian broiler chicken industry sales, it loses over $300,000/year due to mortality from IBH. Hence, the total Canadian broiler industry loss of productivity is much higher, estimated in millions of dollars. We were able to identify that outbreaks of IBH in Canada are primarily due to vertical transmission of FAdVs from their parents. We were also able to demonstrate that five major serotypes of FAdVs cause IBH across Canada and there is a significant protection of broilers against IBH by vaccinating broiler breeders with either inactivated or live FAdV vaccine. Although, we were able to produce two prototype vaccines against IBH with financial support from industry and NSERC, we need to optimize these inactivated and live FAdV vaccines to improve their efficacy before they can be manufactured and become commercially available to the broiler industry in Canada. This proposed research will optimize both live and inactivated FAdV vaccines, and improve our understanding of FAdV shedding and mutational changes of FAdV at the molecular level.