Current egg-based influenza vaccine production technology is labor-intensive and lack of flexibility and its capacity would not be able to meet the demand during influenza pandemics. Therefore, vaccine production using mammalian cell technology is becoming viable and attractive. The current influenza H5N1 vaccine strain (NIBRG-14) could grow efficiently in chicken embroyonated eggs and MDCK cells ( ∼ 10 8 TCID50/ml) but not in Vero cells (10 5—6 TCID50/ml) which is the most common cell line for manufacturing human vaccines. After several passages and plaque purifications, two Vero-adapted high growth influenza H5N1 vaccine viruses (Vero-15 and Vero-16) have been selected and could reach high virus titer (10 8 TCID50/ml) in Vero cells in T flasks. After tested with NIBRG-14 standard antiserum provided by the NIBSC, antigenicity of the Vero-15 and Vero-16 viruses remain similar to the NIBRG-14 virus. In addition, the Vero-15 and Vero-16 viruses do not have any nucleotide difference in HA and NA gene segments compared with the NIBRG-14. For process development, Vero cells were furture cultured on cytodex 1 microcarriers in spinner flasks. Vero cells growed to 3 × 10 6 cells/ml with a seeding density of 4.4 × 10 5 cells/ml in 5 g/L microcarriers and peak virus titers reached 10 9 TCID50/ml. In conclusion, the Vero-15 and Vero-16 viruses are suitable for production of influenza H5N1 vaccines in Vero cells. Their other six internal gene segments could also be used to generate vaccine seed viruses of other influenza subtypes for production in Vero cells.
Date:
2008-12
Relation:
International Journal of Infectious Diseases. 2008 Dec;12(Suppl. 1):E253-E254.
