新城疫基因Ⅶ型多联灭活疫苗的研究

Evaluation of a Multivalent Vaccine Containing Killed Newcastle Disease Virus GenotypeⅦ

本研究旨在研制鸡新城疫(NDV)基因Ⅶ型多联灭活疫苗。利用基因Ⅶ型N7a株病毒液浓缩适当倍数后灭活制备抗原,与浓缩的鸡传染性支气管炎(IB)等抗原等比混合,制备新流二联、新支流三联和新支流法四联苗,免疫SPF鸡评价其近期免疫效力和免疫持续期。结果显示:用浓缩N7a抗原制备的联苗ND HI为8.1~8.4log2,高于未浓缩N7a抗原制备的新支流法四联苗(ND HI为7.4log2);浓缩与未浓缩N7a抗原制备的四联苗IB、AI和IBD抗体无明显差异,浓缩N7a抗原制备的新支流法四联苗免后6个月各组分抗体水平依然达到保护标准。综上,基因Ⅶ型NDV N7a株可用于制备新流二联苗、新支流三联苗和新支流法四联苗,不同组分之间抗原相容性好,且新支流法四联苗的免疫持续期可达6个月。

This study aimed to develop a multiple inactivated vaccine for prevention of Newcastle disease(ND)genotype VII in chickens.The antigens were prepared by inactivating the concentrated genotype VII N7a strain viruses and mixing with killed chicken infectious bronchitis(IB)antigens in equal volume to prepare bivalent,trivalent and quadrivalent vaccines.These vaccines were used to immunize SPF chickens to evaluate the short-term immune effect and duration.The results showed that the ND HI titer of the combined vaccine prepared with concentrated N7a antigen was 8.1-8.4 log2,which was higher than that of the quadrivalent vaccine prepared without concentrated N7a antigen(ND HI 7.4 log2).There was no significant difference in the IB,AI and IBD antibodies of the combined vaccine,and the antibody level of each component of the quadrivalent vaccine prepared with concentrated N7a antigen still reached the six-month protection standard.In conclusion,the NDV genotype VII N7a strain could be used to prepare ND-AI bivalent,ND-IB-AI trivalent and ND-IB-AI-IBD quadrivalent vaccines with good antigenic compatibility among the different components.The new ND-IB-AI-IBD quadrivalent vaccine provided protection up to 6 months for chickens.