水禽用H5亚型禽流感灭活疫苗对高致病性禽流感病毒流行毒株的免疫保护效果研究

为评价水禽用禽流感灭活疫苗(H5N2亚型,D7株)对2010年以后分离的高致病性禽流感病毒流行毒株的免疫保护效果,将该疫苗免疫3周龄SPF鸭后,21 d采血、分离血清测定HI抗体效价,同时用5株2010年以后分离的高致病性禽流感流行毒进行攻毒保护试验,攻毒后5d采集所有试验鸭喉头和泄殖腔拭子进行病毒分离.结果显示,该疫苗免疫SPF鸭21 d后的HI抗体效价的几何平均滴度达7.4log2,对5株高致病性禽流感病毒的攻击均可产生良好的免疫保护,并有效阻止病毒排泄.该疫苗的推广使用将对我国水禽高致病性禽流感的防控发挥重要作用.

Protective Efficacy of an H5 subtype Avian Influenza Inactivated Vaccine in Waterfowl after Challenge with Recent HPAI Viruses

The protective efficacy of the inactivated avian influenza virus (AIV) H5N2 subtype vaccine (D7) for waterfowl against the high pathogenic avian influenza(HPAI) virus strains isolated since 2010 were evaluated in SPF ducks which were immunized with D7 inactivated vaccine when they were 3 weeks old. The hemagglutinin-inhibition (HI) antibody was detected and the ducks were challenged with 5 high pathogenic avian influenza virus strains isolated since 2010 at 21 days post vaccination (p.v). The larynx and cloaca swabs were collected for virus isolation at 5 days post challenge. The results showed that D7 vaccine induced strong immune response in ducks with a geometric mean titre of HI antibody up to 7.4log2 at 21 days p.v. The vaccine can produce a good protective effect at SPF ducks from challenge and prevent the excretion of the viruses. The vaccine is important for prevention and control of HPAI in waterfowl in China.