Key Laboratory of Animal Epidemiology of the Ministry of Agriculture, College of Veterinary Medicine, China Agricultural University, Beijing 100193, People's Republic of China.
Beijing Huadu Yukou Poultry Company Limited, Beijing 101206, People's Republic of China.
Vaccine. 2018 Mar 27;36(14):1880-1886. doi: 10.1016/j.vaccine.2018.02.053. Epub 2018 Feb 26.
Avian infectious bronchitis (IB) is a highly contagious disease caused by avian infectious bronchitis virus (IBV), which is a considerable economic threat to the poultry industry. QX-like IBV strains have increasingly emerged in China in recent years. Hence, development of a specific vaccine to guard against their potential threat is important. In this study, we sought to develop an attenuated vaccine strain. First, attenuated QX-like IBV strain SZ130 was created by continuous passage in chicken embryos for 130 generations, and then its safety was tested. We also evaluated the protective efficacy of different doses of SZ130 against challenge with QX-like IBV field strain SD in chickens. SZ130-infected birds did not experience IB-like signs and organ lesions. Additionally, an excellent protective effect of SZ130 vaccination was observed when vaccinated birds were challenged with SD, with no clinical signs or gross lesions, decreased target tissue replication rates, and lower ciliostasis scores in all immunized groups. These findings indicate that attenuated IBV strain SZ130 is highly safe in chicks and may serve as an effective vaccine against the threat posed by QX-like IBV strains.
鸡传染性支气管炎（IB）是由禽传染性支气管炎病毒（IBV）引起的高度传染性疾病，对家禽业构成重大经济威胁。近年来，QX 样 IBV 株在中国不断出现。因此，开发针对其潜在威胁的特异性疫苗非常重要。在本研究中，我们试图开发一种减毒疫苗株。首先，通过在鸡胚中连续传代 130 代，创建了减毒 QX 样 IBV 株 SZ130，然后测试了其安全性。我们还评估了不同剂量的 SZ130 对鸡接种 QX 样 IBV 田间株 SD 后的保护效力。感染 SZ130 的鸡没有出现 IB 样症状和器官病变。此外，当用 SD 攻毒接种鸡时，SZ130 接种显示出极好的保护效果，所有免疫组均无临床症状或大体病变，靶组织复制率降低，纤毛静止评分降低。这些发现表明，减毒 IBV 株 SZ130 在雏鸡中非常安全，可能成为针对 QX 样 IBV 株威胁的有效疫苗。
