Capturing of cell culture derived influenza viruses by sulphated cellulose membranes – a promising pseudo-affinity method for influenza vaccine production

Influenza is a global disease causing several million infections in humans every year. One of the most effective methods in controlling seasonal influenza epidemics is prophylactic vaccination, which requires fast, effective and reliable processes to produce large amounts of vaccine doses every year. Traditionally, the production of human influenza vaccines is based on the growth of viruses in embryonated chicken eggs. However, several limitations are associated with this method including low efficiency, limited scalability and potential allergic reactions induced by egg proteins. Hence, mammalian cell culture based vaccine production has been developed requiring new downstream process strategies for virus purification. The presented study focused on the development of a pseudo-affinity capture step for Madin Darby canine kidney (MDCK) cell culture derived influenza viruses by sulphated cellulose membranes. Extensive purification studies were done using different influenza virus strains including two strains from the season 2007/2008 (A/Wisconsin/67/2005 (subtype H3N2), B/Malaysia/2506/2004) and A/Puerto Rico/8/34 (subtype H1N1). Viral recoveries based on hemagglutination activity (HA), as well as reduction of host cell dsDNA and total protein were directly compared to results obtained with commercially available cation exchange membrane adsorbers and cellufineTM sulphate. With the modified cellulose membranes a higher viral product recovery was achieved than with cellufineTM sulphate and the cation exchange membrane adsorbers, respectively. Due to the low back pressure and fast binding kinetics allowing significantly higher flow rates, sulfated cellulose membranes are economically favorable over column based media such as cellufineTM sulphate. Therefore, sulphated cellulose membranes seem to be an attractive tool for industrial downstream processing of influenza virus in vaccine production. They might even have the potential to replace column based matrix cellufineTM sulphate, which is commonly used for virus purification