Rabies veterinary virus vaccine produced in BHK-21 cells grown on microcarriers in a bioreactor

BHK-21 cells were grown in microcarriers in the CELLIGEN CL 50 bioreactor to produce a stock of rabies veterinary virus vaccine PV (Pasteur virus) strain. Perfusion mode operation of this bioreactor produced between two- and fourfold larger yields (cells/ml) than traditional stationary cell culture systems (i.e., Blake, and Roller bottles or cell factory multitrays). The method employed harvested 281 of rabies virus in 200 h (infectivity titer 0.6 +/- 1.4 x 10(7) LD50 per ml) in a single operation. The risk of contamination is thus reduced when compared with traditional stationary methods which, in order to obtain the same amount of virus, would require the operation of 285 Blake bottles, or 143 Roller bottles, or 15 Cell Factory multitrays (10 trays). By perfusion mode operation of the bioreactor, 89% of the cell culture medium was recovered as vaccinal virus, which contrasts with the yield of only 50-59% using traditional cell culture systems. On the other hand, only 925 ml of fetal serum was required to obtain the 281 of rabies virus harvest as compared to the 3420 ml required by traditional methods.