Integrated production of an influenza A vaccine candidate with MDCK
suspension cells
Abstract
Seasonal influenza infection waves occur both in northern and southern
hemispheres every year. Despite the differences in influenza virus
surface antigens and virulence of seasonal subtypes, manufacturers are
well-adapted to respond to this periodical vaccine demand. Due to
decades of influenza virus research, the development of new influenza
vaccines is relatively straight-forward. Nevertheless, compared to the
recent Covid-19 pandemic where a vaccine is not yet available, influenza
vaccine manufacturing would be a major bottleneck for the rapid supply
of billions of doses required worldwide. In particular, egg-based
vaccine production would be difficult to schedule and shortages of other
egg-based vaccines with high demands also have to be anticipated. Cell
culture-based production systems enable manufacturing of large amounts
of vaccines within a short time frame and expand significantly our
options to respond to pandemics and emerging viral diseases. In this
work, we present an integrated process for the production of inactivated
influenza A virus vaccines based on a MDCK suspension cell line
cultivated in a chemically defined medium. Very high titers of 3.6
log10(HAU/100 µL) were achieved using fast growing MDCK cells at
concentrations up to 9.5 × 106 cells/mL infected with influenza
A/PR/8/34 H1N1 virus in 1 L stirred tank bioreactors. A combination of
two membrane-based chromatography steps enabled full recovery for the
virus capture and up to 80 % recovery for the virus polishing step,
respectively. Purified virus particles showed a homogenous size
distribution around a mean diameter of 80 nm. Based on a monovalent dose
of 15 µg hemagglutinin (SRID assay), the level of total protein was 58
µg and the level of host cell DNA contamination was below 10 ng.
Furthermore, all process steps can be fully scaled up to industrial
quantities for commercial manufacturing of either seasonal or pandemic
influenza virus vaccines. Fast production of up to 300 vaccine doses per
liter within 4 to 5 days makes this process competitive not only to
other cell-based processes, but to egg-based processes as well.