An Industrial Platform for Purifying Influenza Virus Particles

Avir Green Hills Biotechnology is developing innovative seasonal and pandemic influenza vaccines based on the deletion of the NS1 gene (delNS1 vaccine). The vaccine is replication-defective and applied intranasally. Currently, an H1N1 monovalent vaccine is being tested in a clinical phase I study, with an H5N1 avian influenza vaccine soon to be initiated. A production and purification process, which was successfully employed for the pilot-scale production of H1N1 and H5N1 influenza A vaccine virus, will be presented. Data on the selection of chromatographic media, relevant to eliminate downstream purification bottlenecks will also be discussed.

Details on obtained virus yields as well as impurity removal will be given. The vaccine virus is produced in static cell culture using Vero (African Green monkey kidney) cells. After clarification the vaccine virus bulk is purified using the same scheme for all different subtypes: Concentration by tangential ultra filtration, AEX chromatography using a CIM QA monolith, and an SEC polishing step allowing for buffer exchange. This purification scheme guarantees the thorough depletion of host cell DNA and total protein. In addition, an HPLC method for quantifying influenza virus in the vaccine with the use of CIM monolithic columns will be presented and the results will be compared with haemagglutination method.