The stability of vero cell adapted HAV strain (YN5) during passage cultivation

To investigate the stability of HAV adapted strain( YN5)of Vero cell in pilot scale, serial passage was used to carry out 24 d adaptability cultivation. It showed that the titre increased progressively and tended to stable after 18 th generation. The infective titre reached 8.67 LogCCID_(50)/mL and antigen titre reached 1:4 096 at 23 rd generation. The immunogenicity of the deactivated vaccine precipitated by the virus strain of 25 th generation is fine, while antigen proliferation level was stable after continuous 3 batches of pilot scale production.It demonstrated that HAV YN5 , whose conservation and proliferation were stable, had already adapted to Vero cell ,and it ensured the large scale manufacture effectively in future.