5.6

Cultivation Vessels at Small and Larger Scale and Process Variables ...102

5.6.1 Cultivation Vessels.......................................................................102

5.6.2 Process Variables .........................................................................105

5.6.2.1 Temperature...................................................................106

5.6.2.2 pH and CO2 ...................................................................106

5.6.2.3 Shear Stress....................................................................106

5.6.2.4 Oxygen Supply ..............................................................107

5.6.3 Choosing a Production Vessel.....................................................110

5.7

Virus Production and Process Development.............................................110

5.7.1 Virus Production...........................................................................110

5.7.2 Process Development and Optimization......................................112

5.7.2.1 Seed Virus Generation ..................................................113

5.7.2.2 Process Optimization Options.......................................113

5.8

Sometimes Nothing Makes Sense—Some Ideas on Trouble Shooting…119

5.9

CMC and GMP Considerations Right from the Start...............................120

5.9.1 Cellular Sources ...........................................................................122

5.9.2 Virus Sources ...............................................................................123

5.9.3 Cell Growth and Harvesting........................................................123

5.9.4 Purification and Downstream Processing....................................124

5.10

Other Points to Consider............................................................................125

5.10.1 Manufacturing Options.................................................................125

5.10.2 Biosafety.......................................................................................125

5.11

Conclusion..................................................................................................127

References..............................................................................................................127

SYMBOLS

CSVY

Cell-specific virus yield

virions/cell

Cvir

Virus particle concentration

virions/mL

CO2

Oxygen saturation concentration

mM

CO2

Actual oxygen concentration

mM

Cs

Substrate concentration

mM

Cx

Cell concentration

cells/mL

η

Dynamic viscosity

Pa s

kLa

Volumetric mass transfer coefficient

1/h

MOI

Multiplicity of infection

infectious units/cell

OTR

Oxygen transfer rate

mM/h

PFU

Plaque forming units

PFU/mL

pO2

Partial pressure of oxygen

%

rpm

Rounds per minute

rpm

τ

Shear stress

Pa

TCID50

Tissue culture infectious dose 50

TCID50/mL

TOH

Time of harvest

h

TOI

Time of infection

h

80

Bioprocessing of Viral Vaccines