Newcastle disease (ND) is one of the most important and devastating avian diseases with considerable threat to the global poultry industry. Hepatitis-hydropericardium syndrome (HHS), caused by virulent fowl adenovirus serotype 4 (FAdV-4), is another highly infectious disease in chickens with severe economic impact. The effective way to combat ND and HHS is by vaccinating the poultry. In the present study, a recombinant NDV LaSota vaccine strain expressing full length fiber-2 gene of FAdV-4 (rLaSota-fiber2) was generated using reverse genetics. The FAdV-4 fiber-2 protein was expressed as a soluble form rather than NDV membrane-anchored form. The rLaSota-fiber2 was genetically stable, and it showed growth patterns in embryonated eggs comparable to that of parental rLaSota virus. Since our unpublished data demonstrated that delivery of live rLaSota-fiber2 in drinking water or ocular delivery of the vaccine didn't produce protection against hypervirulent FAdV-4 challenge, even though the vaccine provide full protection against NDV challenge, the efficacy of the rLaSota-fiber2 was evaluated by delivering the vaccine intramuscularly in this study. Single-dose intramuscular vaccination of 2-week-old SPF White Leghorn chicks with the live or inactivated rLaSota-fiber2 provided complete protection against virulent NDV challenge. However, single-dose intramuscular vaccination with the live rLaSota-fiber2 vaccine provided better protection against virulent FAdV-4 challenge and significantly reduced faecal viral shedding comparing to the inactivated vaccine. These results indicate that the NDV-vectored FAdV-4 vaccine is a promising bivalent vaccine candidate to control both HHS and ND.

中文翻译：

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表达鸡腺病毒血清型4纤维2蛋白的重组新城疫病毒疫苗，可保护鸡免受肝炎，心包水综合征和新城疫的侵害。

新城疫（ND）是最重要和最具破坏力的禽类疾病之一，对全球家禽业构成重大威胁。由强毒禽腺病毒血清型4（FAdV-4）引起的肝炎－水囊病综合症（HHS）是对鸡的另一种高度传染性疾病，具有严重的经济影响。防治ND和HHS的有效方法是给家禽接种疫苗。在本研究中，使用反向遗传学产生了表达FAdV-4的全长纤维2基因（rLaSota-fiber2）的重组NDV LaSota疫苗株。FAdV-4纤维2蛋白表达为可溶形式，而不是NDV膜锚定形式。rLaSota-fiber2具有遗传稳定性，并且在胚胎卵中显示的生长模式与亲代rLaSota病毒相当。由于我们未公开的数据表明，在饮用水中分娩活rLaSota-fiber2或经眼部递送疫苗均未产生针对高毒FAdV-4攻击的保护作用，即使该疫苗提供了针对NDV攻击的全面保护，因此rLaSota-在这项研究中通过肌内注射疫苗评估了fibre2。用活的或灭活的rLaSota-fiber2对2周龄的SPF White Leghorn雏鸡进行单剂量肌内疫苗接种可提供针对强毒NDV攻击的全面保护。但是，与灭活疫苗相比，用活rLaSota-fiber2疫苗进行单剂量肌内疫苗接种可提供更好的保护，以抵抗强毒FAdV-4攻击，并显着减少粪便病毒脱落。