Determination of appropriate time to havest FMD antigen, type A in fermentation pot system

Abstract

In this research, we conducted the experiments to optimize the process of culturing BHK21 suspension cells in the fermentation pot system and then infected FMD virus, type A
and harvested the antigens meeting the technical requirements to serve for the production
of oil inactivated vaccines. The BHK-21 seed cells were cultured continuously through many
generations, then transferred to the culture tank system. The maximum cell growth in number
and density was 2.8 x 106 cells/ml after 36 hours. This was the time to infect FMD virus A-AVAC
1, A-AVAC 2 with the infectious dose was determined at 0.005 MOI to obtain antigens with virus
titer greater than 107.5 TCID50/ml. We titrated the virus titer by time and achieved the highest
viral titer of 107.77 TCID50/ml at the time from 18 hours to 24 hours. This time was the most
appropriate milestone to harvest FMD antigens of 2 trains, type A meeting quality requirements,
which is a prerequisite for production of FMD oil inactivated vaccine