China Animal Husbandry and Veterinary Medicine ›› 2023, Vol. 50 ›› Issue (12): 5013-5021.doi: 10.16431/j.cnki.1671-7236.2023.12.023

• Preventive Veterinary Medicine • Previous Articles     Next Articles

Isolation,Identification of H9 Subtype Avian Influenza Virus and Immune Protection Effect of Inactivated Trivalent Vaccine of Newcastle Disease,Avian Influenza (H9 Subtype),and Avian Adenovirus Disease Against the Viruses

JIN Huan, TU Min, SHI Aihua, ZHAO Lei, SHEN Jia, XI Shuo, ZHANG Jianwei, ZHANG Zhenhua   

  1. Institute of Animal Husbandry and Veterinary Medicine, Beijing Academy of Agriculture and Forestry Sciences, Beijing 100097, China
  • Revised:2023-09-20 Online:2023-12-05 Published:2023-11-28
  • Contact: 国家自然科学基金青年基金(32202793);北京市农林科学院青年基金(QNJJ202111);北京市农林科学院创新能力建设(KJCX20230424) E-mail:13401014936@163.com
  • Supported by:
    The project was supported by the National Key Research and Development Program of China (2019YFC1905301);National Natural Science Foundation of China (22078115,21776108,21690083,22008078).

Abstract: 【Objective】 The aim of the experiment was to study the immune protection effect of the inactivated trivalent vaccine (La Sota strain+BX13 strain+DC strain) of Newcastle disease,avian influenza (H9 subtype),and Avian adenovirus disease (group Ⅰ,type 4) on epidemic strains of Avian influenza virus (AIV),and provide the data for supporting the research of the inactived trivalent vaccine.【Method】 In this study,AIV was isolated and identified in samples collected from infected chickens in Shijiazhuang-Hebei,Miyun-Beijing,Hengshui-Hebei and Nanning-Guangxi during 2019-2022.The MegAlign software was used to analyze the similarity and phylogenetic relationship among the BX13 and the isolated strains from 2019 to 2022.SPF chickens were immunized with the inactivated trivalent vaccine and the serum was collected to determine the HI titer 21 d after immunization.At the same time,a challenge test was conducted using the homologous BX13 strain and the AIV isolates in this experiment to test the protective effect of the inactivated trivalent vaccine on the H9 subtype AIV epidemic strains.【Result】 Four strains of AIV were isolated from Hebei,Beijing and Guangxi from 2019 to 2022,all of which were H9 subtype AIVs,named SJZ19,MY20,HS21 and NN22 strains, respectively.The similarity among the BX13 strain and the four isolated strains from 2019 to 2022 was relatively high,ranging from 95.3% to 96.3%.BX13 strain and 4 isolates all belonged to the branch of DK-HK-Y280-97.After being immunized with the inactivated trivalent vaccine,the HI antibody titers of the H9 subtype AIV in chickens of each immunization group significantly increased,reaching 9.2-9.9 log2,while the control group showed negative antibodies.After being challenged with homologous BX13 strain,100% (5/5) of chickens in control group were positive,while 100% (10/10) of chickens in immune group were negative,with a protection rate of 100%.After being challenged with four H9 subtype AIV isolates,chickens in control group were 100% (5/5) positive,while chickens in immune group were 90% (9/10) to 100% (10/10) negative,with a protection rate of 90% to 100%.【Conclusion】 The inactivated trivalent vaccine prepared by BX13 strain had good immune protection effect on the current epidemic virus strains.

Key words: H9 subtype Avian influenza virus; epidemic strains; inactivated trivalent vaccine; immune protection

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