title: Production of inactivated influenza H5N1 vaccines from MDCK cells in serum-free medium.
abstract: BACKGROUND
  Highly pathogenic influenza viruses pose a constant threat which could lead to a global pandemic. Vaccination remains the principal measure to reduce morbidity and mortality from such pandemics. The availability and surging demand for pandemic vaccines needs to be addressed in the preparedness plans. This study presents an improved high-yield manufacturing process for the inactivated influenza H5N1 vaccines using Madin-Darby canine kidney (MDCK) cells grown in a serum-free (SF) medium microcarrier cell culture system.
  
  
  RESULTS
  The current study has evaluated the performance of cell adaptation switched from serum-containing (SC) medium to several commercial SF media. The selected SF medium was further evaluated in various bioreactor culture systems for process scale-up evaluation. No significant difference was found in the cell growth in different sizes of bioreactors studied. In the 7.5 L bioreactor runs, the cell concentration reached to 2.3 × 10(6) cells/mL after 5 days. The maximum virus titers of 1024 Hemagglutinin (HA) units/50 µL and 7.1 ± 0.3 × 10(8) pfu/mL were obtained after 3 days infection. The concentration of HA antigen as determined by SRID was found to be 14.1 µg/mL which was higher than those obtained from the SC medium. A mouse immunogenicity study showed that the formalin-inactivated purified SF vaccine candidate formulated with alum adjuvant could induce protective level of virus neutralization titers similar to those obtained from the SC medium. In addition, the H5N1 viruses produced from either SC or SF media showed the same antigenic reactivity with the NIBRG14 standard antisera.
  
  
  CONCLUSIONS
  The advantages of this SF cell-based manufacturing process could reduce the animal serum contamination, the cost and lot-to-lot variation of SC medium production. This study provides useful information to manufacturers that are planning to use SF medium for cell-based influenza vaccine production.
authors.affiliation: Vaccine Research and Development Center, National Health Research Institutes, Zhunan, Taiwan Authority.
authors.forename: Alan Yung-Chih
authors.initials: AY
authors.lastname: Hu
authors.forename: Yu-Fen
authors.initials: YF
authors.lastname: Tseng
authors.forename: Tsai-Chuan
authors.initials: TC
authors.lastname: Weng
authors.forename: Chien-Chun
authors.initials: CC
authors.lastname: Liao
authors.forename: Johnson
authors.initials: J
authors.lastname: Wu
authors.forename: Ai-Hsiang
authors.initials: AH
authors.lastname: Chou
authors.forename: Hsin-Ju
authors.initials: HJ
authors.lastname: Chao
authors.forename: Anna
authors.initials: A
authors.lastname: Gu
authors.forename: Janice
authors.initials: J
authors.lastname: Chen
authors.forename: Su-Chen
authors.initials: SC
authors.lastname: Lin
authors.forename: Chia-Hsin
authors.initials: CH
authors.lastname: Hsiao
authors.forename: Suh-Chin
authors.initials: SC
authors.lastname: Wu
authors.forename: Pele
authors.initials: P
authors.lastname: Chong
mesh_terms: D000818:Animals; D019149:Bioreactors; D001717:Birds; D018929:Cell Culture Techniques / Q000379:methods; D002460:Cell Line; D049109:Cell Proliferation; D016895:Culture Media, Serum-Free; D004285:Dogs; D053124:Influenza A Virus, H5N1 Subtype / Q000254:growth & development*; D007252:Influenza Vaccines / Q000096:biosynthesis*; D005585:Influenza in Birds / Q000517:prevention & control*; D058873:Pandemics; D015164:Vaccines, Inactivated / Q000096:biosynthesis*
chemical_list: D016895:Culture Media, Serum-Free; D007252:Influenza Vaccines; D015164:Vaccines, Inactivated