title: Improved poliovirus D-antigen yields by application of different Vero cell cultivation methods.
abstract: Vero cells were grown adherent to microcarriers (Cytodex 1; 3 g L(-1)) using animal component free media in stirred-tank type bioreactors. Different strategies for media refreshment, daily media replacement (semi-batch), continuous media replacement (perfusion) and recirculation of media, were compared with batch cultivation. Cell densities increased using a feed strategy from 1×10(6) cells mL(-1) during batch cultivation to 1.8, 2.7 and 5.0×10(6) cells mL(-1) during semi-batch, perfusion and recirculation, respectively. The effects of these different cell culture strategies on subsequent poliovirus production were investigated. Increased cell densities allowed up to 3 times higher D-antigen levels when compared with that obtained from batch-wise Vero cell culture. However, the cell specific D-antigen production was lower when cells were infected at higher cell densities. This cell density effect is in good agreement with observations for different cell lines and virus types. From the evaluated alternative culture methods, application of a semi-batch mode of operations allowed the highest cell specific D-antigen production. The increased product yields that can easily be reached using these higher cell density cultivation methods, showed the possibility for better use of bioreactor capacity for the manufacturing of polio vaccines to ultimately reduce vaccine cost per dose. Further, the use of animal-component-free cell- and virus culture media shows opportunities for modernization of human viral vaccine manufacturing.
authors.affiliation: Institute for Translational Vaccinology, Process Development, PO BOX 450, Bilthoven 3720 AL, The Netherlands.
authors.forename: Yvonne E
authors.initials: YE
authors.lastname: Thomassen
authors.affiliation: Institute for Translational Vaccinology, Process Development, PO BOX 450, Bilthoven 3720 AL, The Netherlands.
authors.forename: Olaf
authors.initials: O
authors.lastname: Rubingh
authors.affiliation: Wageningen University, Bioprocess Engineering, PO BOX 8129, Wageningen 6700 EV, The Netherlands.
authors.forename: René H
authors.initials: RH
authors.lastname: Wijffels
authors.affiliation: Institute for Translational Vaccinology, Process Development, PO BOX 450, Bilthoven 3720 AL, The Netherlands.
authors.forename: Leo A
authors.initials: LA
authors.lastname: van der Pol
authors.affiliation: Institute for Translational Vaccinology, Process Development, PO BOX 450, Bilthoven 3720 AL, The Netherlands. Electronic address: wilfried.bakker@intravacc.nl.
authors.forename: Wilfried A M
authors.initials: WA
authors.lastname: Bakker
mesh_terms: D000818:Animals; D000956:Antigens, Viral / Q000302:isolation & purification*; D019149:Bioreactors; D002452:Cell Count; D018929:Cell Culture Techniques / Q000379:methods*; D002522:Chlorocebus aethiops; D003470:Culture Media / Q000737:chemistry; D017955:Poliovirus / Q000254:growth & development*; D014709:Vero Cells; D014776:Virus Cultivation / Q000379:methods*
chemical_list: D000956:Antigens, Viral; D003470:Culture Media
keywords: Adherent; Batch; Feed; Microcarriers; Perfusion; Recirculation