title: Evaluation of a microcarrier process for large-scale cultivation of attenuated hepatitis A.
abstract: Microcarrier culture was investigated for the propagation of attenuated hepatitis A vaccine in the anchorage-dependent human fibroblast cell line, MRC-5. Cells were cultivated at 37 degrees C for one to two weeks, while virus accumulation was performed at 32 degrees C over 21 to 28 days. The major development focus for the microcarrier process was the difference between the cell and virus growth phases. Virus antigen yields, growth kinetics, and cell layer/bead morphology were each examined and compared for both the microcarrier and stationary T-flask cultures. Overall, cell densities of 4-5 x 10(6) cells/ml at 5-10 milligrams beads were readily attained and could be maintained in the absence of infection at either 37 degrees C or 32 degrees C. Upon virus inoculation, however, substantial cell density decreases were observed as well as 2.5 to 10-fold lower per cell and per unit surface area antigen yields as compared to stationary cultures. The advantages as well as the problems presented by the microcarrier approach will be discussed.
authors.affiliation: Merck Research Laboratories, Rahway, New Jersey.
authors.forename: B H
authors.initials: BH
authors.lastname: Junker
authors.forename: F
authors.initials: F
authors.lastname: Wu
authors.forename: S
authors.initials: S
authors.lastname: Wang
authors.forename: J
authors.initials: J
authors.lastname: Waterbury
authors.forename: G
authors.initials: G
authors.lastname: Hunt
authors.forename: J
authors.initials: J
authors.lastname: Hennessey
authors.forename: J
authors.initials: J
authors.lastname: Aunins
authors.forename: J
authors.initials: J
authors.lastname: Lewis
authors.forename: M
authors.initials: M
authors.lastname: Silberklang
authors.forename: B C
authors.initials: BC
authors.lastname: Buckland
mesh_terms: D000956:Antigens, Viral / Q000032:analysis; D001709:Biotechnology / Q000295:instrumentation*; D002448:Cell Adhesion / Q000502:physiology; D002452:Cell Count; D002455:Cell Division / Q000502:physiology; D002460:Cell Line; D003911:Dextrans; D005452:Fluoresceins; D022362:Hepatitis A Vaccines; D006507:Hepatovirus / Q000254:growth & development*; D006358:Hot Temperature; D006801:Humans; D008863:Microspheres; D015203:Reproducibility of Results; D014613:Vaccines, Attenuated / Q000096:biosynthesis; D014761:Viral Hepatitis Vaccines / Q000096:biosynthesis
chemical_list: D000956:Antigens, Viral; D003911:Dextrans; D005452:Fluoresceins; D022362:Hepatitis A Vaccines; D014613:Vaccines, Attenuated; D014761:Viral Hepatitis Vaccines; C052839:Cytodex; C018506:diacetylfluorescein