Virus filtration in biopharmaceutical downstream processes: key factors and current limitations

Virus clearance, a critical aspect of biopharmaceutical manufacturing processes, ensures the safety of biopharmaceutics. Virus filtration is widely used during biopharmaceutical downstream processes to remove viruses effectively by separating small viruses (e.g., parvovirus with a size of 18–26 nm) from biopharmaceutics (e.g., monoclonal antibodies with a size of ~12 nm) based on a size-exclusion mechanism (i.e., more than 4-log10 removal of viruses with high product recovery). This paper presents a review of key factors such as filter morphology, feed solution composition, and the performance of high-throughput virus filtration, mainly focusing on the log reduction value for virus removal efficiency. Flow interruption and protein fouling issues are also discussed.