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Abstract

Production of animal cell culture derived influenza virus seems to be suitable for industrial scale production of human vaccines to prevent pandemics. The bioprocess engineering group at the MPI Magdeburg works on a process with MDCK cells focusing on different aspects like virus replication, cell physiology, proteomics a. o.. For possible comparative studies the establishment of the alternative production process with Vero cells, as described in literature, was the aim of this work. Experiments regarding cell growth and virus replication were carried out in static and microcarrier systems. The influence of multiplicity of infection (moi) and trypsin concentration on infection in several media (serum containing/serum free) were experimentally investigated. It was seen, that the moi had an influence on the course of infection but not on the virus yield. The trypsin concentration for infection had to be adapted to each medium and cultivation system for optimization of the virus yield. A twofold higher concentration of trypsin was necessary in serum free media. By adapting the virus to the Vero cells, virus yield as well as infection course could be improved. The comparison of two bioreactors (Wave Bioreactor/5 L stirred tank reactor) showed a higher virus yield for cultivation in Wave Bioreactor. For standard cultivation (2 g/L microcarriers) in Wave, cell densities of 1.0*106 cells/mL and virus yield of about 2.3 log HA units/100µL were reached. The cultivations in 5 L stirred tank reactor showed higher cell densities (1.7*106 cell/mL) but lower virus titers (1.6 log HA unit/100µL). Metabolic activity (Glucose, Lactat, Glutamine, Ammonia and Glutamat) was higher in Wave. A high cell density cultivation in Wave (4 g/L microcarriers) showed an increase of virus production with higher cell densities (2.2*106 cells/mL, 2.9 log HA units/100µL). No cell density effect was detectable. The obtained data on cell growth, metabolism and virus production for the process with Vero cells were compared to the data on MDCK cells and can be used to set-up further experiments for comparative studies.