Emerging Hypervirulent Marek's Disease Virus Variants Significantly Overcome Protection Conferred by Commercial Vaccines.
Emerging Hypervirulent Marek's Disease Virus Variants Significantly Overcome Protection Conferred by Commercial Vaccines.
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DOI：
10.3390/v15071434
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发表时间：
2023-06-25
期刊：
影响因子：
--
通讯作者：
Luo J
中科院分区：
文献类型：
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作者：
Liu JL;Teng M;Zheng LP;Zhu FX;Ma SX;Li LY;Zhang ZH;Chai SJ;Yao Y;Luo J
由致癌性马立克氏病病毒(MDV)引起的马立克氏病(MD)是一种重要的禽类免疫抑制性和肿瘤性疾病，近50年来在全球范围内造成了巨大的经济损失。近年来，马立克氏病在接种MD疫苗的鸡群中暴发频繁，但主要致病决定因素和影响因素尚不清楚。本文对中国地区荷瘤鸡新分离的7株MDV毒株进行了致病性分析，发现它们对鸡宿主均有致病作用，其中SDCW01、HNXZ05、HNSQ05和HNSQ01分离株为超强毒株。病毒感染试验第73天，MD累计发病率分别为100%、93.3%、90%和100%，病死率分别为83.3%、73.3%、60%和86.7%。肿瘤大体发生率分别为50%、33.3%、30%和63.3%，并伴有明显的肝脾肿大和免疫器官严重萎缩。此外，还探讨了四种商品化MD疫苗对SDCW01、CVI988、HVT、CVI988+HVT和814的免疫保护效果。出乎意料的是，在病毒攻击后的67天里，这四种MD疫苗的保护指数(PI)分别只有46.2%、38.5%、50%和28%，接种单价CVI988和HVT的鸡仍然发生了肿瘤，累积发病率分别为7.7%和11.5%。据我们所知，这是首次对不同疫苗株的多种商业化MD疫苗的免疫保护效果进行同时比较。我们的研究表明，中国体内流行的HV-MDV变异体可以显著突破目前广泛使用的经典MD疫苗的免疫保护。在今后的工作中，迫切需要开发新的、更有效的MD疫苗，以应对新出现的HV-MDV毒株或变种的新挑战，以可持续地控制MD。
As one of the most important avian immunosuppressive and neoplastic diseases, Marek’s disease (MD), caused by oncogenic Marek’s disease virus (MDV), has caused huge economic losses worldwide over the past five decades. In recent years, MD outbreaks have occurred frequently in MD-vaccinated chicken flocks, but the key pathogenic determinants and influencing factors remain unclear. Herein, we analyzed the pathogenicity of seven newly isolated MDV strains from tumor-bearing chickens in China and found that all of them were pathogenic to chicken hosts, among which four MDV isolates, SDCW01, HNXZ05, HNSQ05 and HNSQ01, were considered to be hypervirulent MDV (HV-MDV) strains. At 73 days of the virus infection experiment, the cumulative incidences of MD were 100%, 93.3%, 90% and 100%, with mortalities of 83.3%, 73.3%, 60% and 86.7%, respectively, for the four viruses. The gross occurrences of tumors were 50%, 33.3%, 30% and 63.3%, respectively, accompanied by significant hepatosplenomegaly and serious atrophy of the immune organs. Furthermore, the immune protection effects of four commercial MD vaccines against SDCW01, CVI988, HVT, CVI988+HVT, and 814 were explored. Unexpectedly, during the 67 days of post-virus challenge, the protection indices (PIs) of these four MD vaccines were only 46.2%, 38.5%, 50%, and 28%, respectively, and the birds that received the monovalent CVI988 or HVT still developed tumors with cumulative incidences of 7.7% and 11.5%, respectively. To our knowledge, this is the first demonstration of the simultaneous comparison of the immune protection efficacy of multiple commercial MD vaccines with different vaccine strains. Our study revealed that the HV-MDV variants circulating in China could significantly break through the immune protection of the classical MD vaccines currently widely used. For future work, there is an urgent need to develop novel, more effective MD vaccines for tackling the new challenge of emerging HV-MDV strains or variants for the sustainable control of MD.
DOI：
10.3390/v15040817
发表时间：
2023-03-23
期刊：
Viruses
影响因子：
--
作者：
Teng M;Liu JL;Luo Q;Zheng LP;Yao Y;Nair V;Zhang GP;Luo J
通讯作者：
Luo J