摘要
选择当地常用的来自不同厂家的６种新城疫ＩＶ系弱毒苗和３种Ｉ系苗，分别进行免疫效力比较试验。结果，ＩＶ系苗中，Ｄ苗与Ｆ苗组的ＨＩ抗体值显著高于其他各组；Ｉ系苗中，Ａ苗组与Ｂ苗组的ＨＩ抗体值显著高于Ｃ苗组。以上各种新城疫疫苗免疫鸡群后，ＨＩ抗体值虽有差异，但均在临界保护值以上。本试验证明，新城疫的免疫失败或非典型新城疫的发生除要考虑疫苗本身质量外，外部环境及鸡群本身状态也是非常重要的因素。
The immuno effects of six IV strains and three I strains of Newcastle disease (ND)vaccines from different commercial manufacturers were evaluated by testing HI antibody titer of inoculated chickens.All of I strains and IV strains ND vaccines stimulated the chickens to produce an HI antibody titer higher than 1∶16 which normolly considered as the minium protective HI titer against challenge with virulent.ND virus.However,there were significant difference of HI antibody titer level between IV strain vaccines and I strain vaccines.These results indicated that the failures of ND immunity and incidence of non classical ND in field might not be due to the quality of the commercial ND Vaccine,but the other causes which should be investigated.
