流行性乙型脑炎减毒活疫苗生产毒株(SA_(14)-14-2)的稳定性研究

Study on the Stability of the Virus Strains of Japanese Encephalitis Attenuated Live Vaccine

流行性乙型脑炎病毒弱毒株经原代地鼠肾细胞连续传至17代后,毒株蚀斑形态与低代次毒株相似,均为一致的小斑,直径为1mm士,边缘整齐;高代次毒株对成龄小鼠的神经内和神经外毒力未发现增高现象;乳鼠脑内返传一代和返祖试验均未发现高代次较低代次毒力明显升高;不同抗原性的单克隆抗体在与低代和高代次弱毒株的免疫荧光反应中未发现抗原位点变化。

The virus strains (SA_(14)-14-2) which had been undergone 7 to 8 passages (PHK7—8) in primary hamster kidney cells were further cultured to the 17th passages and investigated for their biological and antigenic characteristics. The result showed that the highly passaged virus strains (HK_(17)) were small in plaque size (about 1mm in diameter), and that by i. c. and s. c. inoculation of the neurovirulence did not increase and still remained very low after one back passage in suckling mice brain and atavistic test. All the characteristics were similar to the low-passaged virus strains (HK_(7—8)). When the antigenic sites of the two passaged virus strains were compared by immuno-fluorescence test using 3 different JE McAb, no difference was found between them. The study indicated that the SA_(14)-14-2 virus strains were stable and would not reverse to virulent during the course of passage in the tissue cultures.