马立克氏病(MD),由马立克氏病病毒(MDV)引起,是鸡中常见的传染性肿瘤疾病,也是第一种可通过疫苗接种预防的肿瘤疾病。然而,疫苗不能完全预防致命的MDV感染,允许疫苗和强毒MDV在同一只鸡中长时间共存。本研究旨在使用实时PCR方法研究强毒株Md5和rHVT-IBD疫苗在不同鸡组织中的病毒载量变化。结果表明,rHVT-IBD疫苗显著降低了MDV-Md5在不同器官的病毒载量,而与Md5共感染时,rHVT-IBD的负荷显着增加。此外,在鸡中与Md5和rHVT-IBD共感染不仅改变了两种病毒的原始病毒载量,而且影响了接种后14天Md5的阳性率。阳性率从100%下降到14.29%(羽毛提示),0%(皮肤),33.33%(肝脏),16.67%(脾),28.57%(胸腺),33.33%(法氏囊),和66.67%(PBL),分别。这项研究增强了我们对HVT载体疫苗与鸡中非常强的MDV之间相互作用的理解,并为MD疫苗的未来发展提供了有价值的见解。
Marek\'s disease (MD), caused by the Marek\'s disease virus (MDV), is a common infectious tumor disease in chickens and was the first neoplastic disease preventable by vaccination. However, the vaccine cannot completely prevent virulent MDV infections, allowing both the vaccine and virulent MDV to coexist in the same chicken for extended periods. This study aims to investigate the changes in viral load of the very virulent strain
Md5 and the rHVT-IBD vaccine in different chicken tissues using a real-time PCR assay. The results showed that the rHVT-IBD vaccine significantly reduced the viral load of MDV-
Md5 in different organs, while the load of rHVT-IBD was significantly increased when co-infected with
Md5. Additionally, co-infection with
Md5 and rHVT-IBD in chickens not only changed the original viral load of both viruses but also affected the positive rate of
Md5 at 14 days post-vaccination. The positive rate decreased from 100% to 14.29% (feather tips), 0% (skin), 33.33% (liver), 16.67% (spleen), 28.57% (thymus), 33.33% (bursa), and 66.67% (PBL), respectively. This study enhances our understanding of the interactions between HVT vector vaccines and very virulent MDV in chickens and provides valuable insights for the future development of MD vaccines.