AA-PR8冷适应流感病毒疫苗株的制备及质量评价

Preparation and quality evaluation of AA-PR8 cold-adapted influenza virus vaccine strain

目的制备AA-PR8冷适应流感病毒疫苗株并进行质量评价。方法以A/Ann Arbor/6/60(H2N2)冷适应流感病毒PB2、PB1、PA、NP、M及NS 6个基因作为骨架,与PR8病毒HA、NA基因共同进行病毒拯救,制备AA-PR8冷适应流感病毒疫苗株,并评价其遗传稳定性、温度敏感性、冷适应表型以及在小鼠中的减毒特征。结果成功制备了AA-PR8冷适应流感病毒疫苗株,在鸡胚中传5代后,所有基因氨基酸位点均未发生突变。与PR8野病毒相比,AA-PR8疫苗株可在26℃条件下生长,不能在39℃条件下生长,具有温度敏感性及冷适应表型。与接种同等剂量的PR8野病毒的小鼠相比,接种AA-PR8疫苗株的小鼠体重降低幅度明显减小,未发生动物死亡;肺部病毒载量降低1000倍以上。结论成功制备了遗传稳定性好、具有温度敏感性及冷适应表型、小鼠致病能力弱的AA-PR8冷适应流感病毒疫苗株。

Objective To prepare and evaluate the quality of AA-PR8 cold-adapted influenza virus vaccine strain.Methods PB2,PB1,PA,NP,M and NS genes of A/Ann Arbor/6/60(H2N2)cold-adapted influenza virus were served as skeleton for rescuing the virus cooperatively with HA and NA genes of PR8 virus.The prepared AA-PR8 coldadapted influenza virus vaccine strain was evaluated for genetic stability,temperature sensitivity,cold-adapted phenotype and attenuated characteristic in mice.Results AA-PR8 cold-adapted influenza virus vaccine strain was prepared successfully,which showed no mutation in amino acid sites of all genes after subculture to passage 6 in chick embryo.Compared with PR8 wild virus,AA-PR8 vaccine strain could grow at 26℃,while could not grow at 39℃,indicating the temperature sensitivity and cold-adapted phenotype.Compared with those of mice inoculated with PR8 wild virus at the same dosage,the weight loss of mice inoculated with AA-PR8 vaccine strain decreased significantly with no death,and the viral load in lungs decreased by more than 1000 folds.Conclusion AA-PR8 cold-adapted influenza virus vaccine strain was successfully prepared,which showed good genetic stability,temperature sensitivity,cold-adapted phenotype and low pathogenicity in mice.