title: Selection and characterization of vaccine strain for Enterovirus 71 vaccine development.
abstract: Enterovirus 71 (EV71) has recently emerged as an important neurotropic virus in Asia because effective medications and prophylactic vaccine against EV71 infection are not available. Based on the success of inactivated poliovirus vaccine, the Vero cell-based chemically inactivated EV71 vaccine candidate could be developed. Identification of EV71 vaccine strain which can grow to high titer in Vero cell and induce cross-genotype virus neutralizing antibody responses represents the first step in vaccine development. In this report we describe the characterization and validation of a clinical isolate E59 belonging to B4 sub-genotype based on VP1 genetic analysis. Before selected as the vaccine strain, the genetic stability of E59 in passage had been analyzed based on the nucleotide sequences obtained from the Master Virus Seed, Working Seed banks and the virus harvested from the production lots, and found to be identical to those found in the original isolate. These results indicate that E59 vaccine strain has strong genetic stability in passage. Using this vaccine strain the prototype EV71 vaccine candidate was produced from 20L of Vero cell grown in serum-containing medium. The production processes were investigated, characterized and quantified to establish the potential vaccine manufacturing process including the time for virus harvest, the membrane for diafiltration and concentration, the gel-filtration chromatography for the down-stream virus purification, and the methods for viral inactivation. Finally, the inactivated virion vaccine candidate containing sub-microgram of viral proteins formulated with alum adjuvant was found to induce strong virus neutralizing antibody responses in mice and rabbits. Therefore, these results provide valuable information for cell-based EV71 vaccine development.
authors.affiliation: Vaccine R&D Center, National Institute of Infectious Diseases and Vaccinology, National Health Research Institutes, Zhunan Township, Miaoli County 350, Taiwan.
authors.forename: Jui-Yuan
authors.initials: JY
authors.lastname: Chang
authors.forename: Cheng-Peng
authors.initials: CP
authors.lastname: Chang
authors.forename: Hutchinson Hau-Pong
authors.initials: HH
authors.lastname: Tsai
authors.forename: Chen-Dou
authors.initials: CD
authors.lastname: Lee
authors.forename: Wei-Cheng
authors.initials: WC
authors.lastname: Lian
authors.lastname: Ih-Jen-Su
authors.forename: I-Hsi
authors.initials: IH
authors.lastname: Sai
authors.forename: Chia-Chyi
authors.initials: CC
authors.lastname: Liu
authors.forename: Ai-Hsiang
authors.initials: AH
authors.lastname: Chou
authors.forename: Ya-Jung
authors.initials: YJ
authors.lastname: Lu
authors.forename: Ching-Yao
authors.initials: CY
authors.lastname: Chen
authors.forename: Pi-Hsiu
authors.initials: PH
authors.lastname: Lee
authors.forename: Jen-Ron
authors.initials: JR
authors.lastname: Chiang
authors.forename: Pele Choi-Sing
authors.initials: PC
authors.lastname: Chong
mesh_terms: D000276:Adjuvants, Immunologic / Q000008:administration & dosage; D000534:Alum Compounds / Q000008:administration & dosage; D000818:Animals; D057134:Antibodies, Neutralizing / Q000097:blood; D000914:Antibodies, Viral / Q000097:blood; D002522:Chlorocebus aethiops; D029821:Enterovirus A, Human / Q000235:genetics / Q000254:growth & development / Q000276:immunology* / Q000302:isolation & purification*; D005260:Female; D042822:Genomic Instability; D051379:Mice; D008807:Mice, Inbred BALB C; D012367:RNA, Viral / Q000235:genetics; D017422:Sequence Analysis, DNA; D012692:Serial Passage; D015164:Vaccines, Inactivated / Q000008:administration & dosage / Q000235:genetics / Q000276:immunology / Q000302:isolation & purification; D014709:Vero Cells; D014765:Viral Vaccines / Q000008:administration & dosage / Q000235:genetics / Q000276:immunology* / Q000302:isolation & purification*; D038301:Virus Inactivation
chemical_list: D000276:Adjuvants, Immunologic; D000534:Alum Compounds; D057134:Antibodies, Neutralizing; D000914:Antibodies, Viral; D012367:RNA, Viral; D015164:Vaccines, Inactivated; D014765:Viral Vaccines; C041524:aluminum sulfate