新城疫La Sota疫苗对不同基因型流行株的免疫保护

选取国内2001—2003年发生的5株NDV毒株，经CEF蚀斑纯化和SPF鸡胚增殖，克隆其融合蛋白（F）和血凝素—神经氨酸酶（HN）基因。利用F基因为Ⅱ型的疫苗La Sota活疫苗在隔离器中免疫SPF鸡，每7 d 采血监测NDV抗体，免疫后2周，利用经过鉴定的新城疫病毒（NDV）基因Ⅶ流行株潍坊毒SGM01，昌乐毒SCL03，东营毒SKY和莘县毒SSX03；基因为Ⅱ型日照毒SRZ03和基因为Ⅲ型经典强毒F48E9分别进行攻毒试验，同时设SPF 鸡对照。每天观察，及时剖检发病鸡，检查鸡群病变，观查疫苗的保护性，便于对常规生产中的免疫失败原因进行分析。

Immune protection of newcastle disease La Sota vaccine on different genotypes of newcastle disease isolates

Institute of Poultry Science, Shandong Academy of Agricultural Sciences, Jinan 250100, China)Five isolates of newcastle disease virus prevailed in 2001-2003 in China were collected. These isolateswere purified by CEF plaque assay and replicated in SPF embryos. The fusion protein (F) gene and hemagglutinin-neuraminidase (HN) genes of these viruses were cloned and sequenced. La Sota vaccines with type II F gene wasused to immune SPF group in the isolator. The NDV antibody titers were detected every seven days and chickensincluding SPF control group were challenged by living isolate virus and standard F_(48)E_9 strain after two weeks. It isimportant to autopsy the sickness and dead chickens and ensure the vaccines in order to analyze the immune failurein farm process.