摘要
为评价H9N2亚型禽流感病毒(AIV)NS1基因缺失减毒活疫苗候选株r TX-NS1-128对蛋鸡的免疫效力,本研究对蛋鸡H9N2亚型AIV母源抗体半衰期、疫苗适宜免疫时间、抗体免疫保护临界值以及免疫鸡抗体消长规律等进行研究。结果显示,雏鸡H9亚型AIV母源血凝抑制(HI)抗体半衰期为3.29 d。雏鸡母源抗体水平对疫苗的免疫效果有较大的影响,以母源HI抗体滴度约为4 log2时免疫为宜。少数HI抗体滴度为4 log2~6 log2的免疫鸡攻毒后可在5 d或3 d内从咽喉短暂排毒,HI抗体滴度为4 log2、5 log2、6 log2和≥7 log2时攻毒保护率分别为80%、90%、90%和100%,建议该疫苗的抗体免疫保护临界值为5 log2。鸡一次免疫后平均HI抗体滴度在5 log2以上可持续9周左右。本研究为H9N2亚型禽流感新型减毒活疫苗的开发和应用提供依据。
Abstract： To evaluate the immune efficacy of NSl-truncated live attenuated H9N2 subtype avian influenza virus （AIV） vaccine candidate rTX-NSl-128 strain in layer chickens, the half-life of maternal antibody against H9 subtype AIV, the optimal time for vaccination, the protective threshold antibody titer, and the antibody production and duration in the vaccinated chickens were investigated. The results showed the half-life of maternal hemagglutination inhibition （HI） antibody against H9 subtype A1V in chicks was 3.29 days. The maternal antibody level had a significant influence on the immune efficacy of the vaccine, and vaccination was appropriate when the maternal HI antibody titer declined to around 4 log2. Only few vaccinated chickens with the HI antibody titers ranged from 4 log2 to 6 log2 shed virus by the oropharyngeal route within 5 days or 3 days after challenges, the protective rates of the HI antibody titers of 4 log2, 5 log2, 6 log2 and 〉17 log2 were 80%, 90%, 90% and 100%, respectively. It suggested that the protective threshold of HI antibody titer was 5 log2. The duration of mean HI antibody titer above 5 log2 invaccinated chickens could maintain about 9 weeks after a single vaccination. The results provided the basis for the development and application of the new live attenuated vaccine for prevention of H9N2 subtype avian influenza.
出处
《中国预防兽医学报》
CAS
CSCD
北大核心
2017年第12期998-1002,共5页
Chinese Journal of Preventive Veterinary Medicine
基金
江苏省农业科技自主创新资金项目[CX(15)1065]
江苏省重点研发计划(现代农业)重点项目(BE2016347)
关键词
H9N2亚型禽流感
重组减毒活疫苗
蛋鸡
母源抗体
免疫效力
H9N2 subtype avian influenza
reassortant live attenuated vaccine
layer chickens
maternal antibody
immuneefficacy
作者简介
刘梅（1966-），女，江苏阜宁人，副研究员，硕士，主要从事禽病防治研究．;E—mail：ybdai@163．compengdx@yzu．edu．cn
