Efficient filtration strategies for the clarification of influenza virus-like particles derived from insect cells

Abstract

Vaccination remains the most effective available tool for preventing influenza infection, which affects millions of people annually. The virus is constantly mutating, requiring annual immunization. Vaccine production should be achieved in a very short period to cope with global requirements for seasonal treatment. Moreover, pandemic outbreaks require quick production of large amounts of vaccines. Virus-like particles (VLP) have become a promising alternative for influenza vaccines due to their versatility, immunogenicity and safety profile. However, the diversity of virus surface epitopes contributes to a variability in downstream purification, that could ultimately affect manufacturability and necessitate yearly redevelopment of processes. Therefore, there is a demand for development of better and faster influenza vaccine bioprocesses. Clarification is a critical step, not well characterized for most of the purification processes, but with a strong impact on the downstream performance. For that purpose, we have undertaken an effort to develop a clarification platform for the manufacturing of several influenza strains, mono and multivalent, at different production scales (1L–11L). Both normal and tangential flow filtration approaches were evaluated in terms of product recovery and removal of impurities. The selected clarification train results in essentially 100% product recovery with a turbidity value below 10 NTU, as well as high impurity clearance. Most importantly, these results are independent of strain, cell viability and turbidity at harvest time. The developed clarification framework may be applied to different influenza strains, contributing to a speed-up of vaccine manufacturing.