Patent ID: 8546123

Claim:
A process for the production of poliovirus at a titer of at least 10 10 CCID 50 /mL from a serum-free suspension cell culture, the process comprising: providing a serum-free suspension culture of cells, which cells are primary human retina (HER) cells that have been immortalized by expression of adenovirus E1 sequences; infecting the immortalized HER cells in the serum-free suspension culture, at a cell density of between 5×10 6 cells/mL and 50×10 6 cells/mL, with poliovirus, at a multiplicity of infection (MOI) of between 0.1 and 3 CCID 50 /cell; propagating the poliovirus in the cells, thus producing poliovirus at a titer of at least 10 10 CCID 50 /mL; and harvesting a poliovirus preparation from the infected HER cells at a time of between 12 and 48 hours after infection.