title: Enhancing enterovirus A71 vaccine production yield by microcarrier profusion bioreactor culture.
abstract: Hand, foot and mouth diseases (HFMD) are mainly caused by Enterovirus A71 (EV-A71) infections. Clinical trials in Asia conducted with formalin-inactivated EV-A71 vaccine candidates produced from serum-free Vero cell culture using either roller bottle or cell factory technology, are found to be safe and highly efficacious. To increase vaccine yields and reduce the production costs, the bioprocess improvement for EV-A71 vaccine manufacturing is currently being investigated. The parameters that could affect and enhance the production yields of EV-A71 virus growth in the microcarrier bioreactor were investigated. The medium replacement culture strategy included a multi-harvested semi-batch process and perfusion technology and was found to increase the production yields more than 7-14 folds. Based on the western blot and cryo-EM analyses of the EV-A71 virus particles produced from either the multi-harvested semi-batch (MHSBC) or perfusion cultures were found to be similar to those virus particles obtained from the single batch culture. Mouse immunogenicity studies indicate that the EV-A71 vaccine candidates produced from the perfusion culture have similar potency to those obtained from single batch bioprocess. The physical structures of the EV-A71 particles revealed by the cryo-EM analysis were found to be spherical capsid particles. These results provide feasible technical bioprocesses for increasing virus yields and the scale up of EV-A71 vaccine manufacturing using the bioreactor cell culture methods.
authors.affiliation: National Institute of Infectious Diseases and Vaccinology, National Health Research Institutes, Zhunan Town, Miaoli County, Taiwan. Electronic address: 010113@nhri.org.tw.
authors.forename: Chia-Chyi
authors.initials: CC
authors.lastname: Liu
authors.affiliation: Institute of Biotechnology, Department of Medical Science, National Tsing Hua University, Hsinchu, Taiwan.
authors.forename: Suh-Chin
authors.initials: SC
authors.lastname: Wu
authors.affiliation: Institute of Oral Medicine, College of Medicine, National Cheng Kung University, Tainan, Taiwan.
authors.forename: Shang-Rung
authors.initials: SR
authors.lastname: Wu
authors.affiliation: National Institute of Infectious Diseases and Vaccinology, National Health Research Institutes, Zhunan Town, Miaoli County, Taiwan.
authors.forename: Hsiao-Yu
authors.initials: HY
authors.lastname: Lin
authors.affiliation: National Institute of Infectious Diseases and Vaccinology, National Health Research Institutes, Zhunan Town, Miaoli County, Taiwan.
authors.forename: Meng-Shin
authors.initials: MS
authors.lastname: Guo
authors.affiliation: National Institute of Infectious Diseases and Vaccinology, National Health Research Institutes, Zhunan Town, Miaoli County, Taiwan.
authors.forename: Alan
authors.initials: A
authors.lastname: Yung-Chih Hu
authors.affiliation: National Institute of Infectious Diseases and Vaccinology, National Health Research Institutes, Zhunan Town, Miaoli County, Taiwan; Graduate Institute of Immunology, China Medical University, Taichung, Taiwan.
authors.forename: Yen-Hung
authors.initials: YH
authors.lastname: Chow
authors.affiliation: Vaccine Center, Centers for Disease Control, Taipei, Taiwan.
authors.forename: Jen-Ron
authors.initials: JR
authors.lastname: Chiang
authors.affiliation: Institute of Oral Medicine, College of Medicine, National Cheng Kung University, Tainan, Taiwan.
authors.forename: Dar-Bin
authors.initials: DB
authors.lastname: Shieh
authors.affiliation: National Institute of Infectious Diseases and Vaccinology, National Health Research Institutes, Zhunan Town, Miaoli County, Taiwan; Graduate Institute of Immunology, China Medical University, Taichung, Taiwan.
authors.forename: Pele
authors.initials: P
authors.lastname: Chong
mesh_terms: D000818:Animals; D061249:Batch Cell Culture Techniques; D019149:Bioreactors / Q000821:virology*; D018929:Cell Culture Techniques / Q000379:methods*; D002522:Chlorocebus aethiops; D029821:Enterovirus A, Human / Q000254:growth & development*; D000071497:Immunogenicity, Vaccine; D051379:Mice; D009500:Neutralization Tests; D015164:Vaccines, Inactivated / Q000096:biosynthesis; D014709:Vero Cells; D014765:Viral Vaccines / Q000096:biosynthesis*; D014776:Virus Cultivation / Q000379:methods*
chemical_list: D015164:Vaccines, Inactivated; D014765:Viral Vaccines
keywords: Enterovirus A71; Inactivated whole virion vaccine; Microcarrier culture; Perfusion technology; Serum-free bioreactor