Viral clearance studies are mandatory regulatory studies conducted to demonstrate that a biopharmaceutical manufacturing process is capable of removing or inactivating potential viral contaminants — including both model viruses and relevant viruses — to ensure the safety of the final drug product for patient administration. They are performed by deliberately spiking scaled-down versions of downstream purification unit operations with known quantities of virus and measuring the log reduction value (LRV) achieved at each step — such as low pH inactivation, nanofiltration, and chromatography. Viral clearance studies are required by regulatory agencies including the European Medicines Agency (EMA) and Food and Drug Administration (FDA) in accordance with ICH Q5A guidelines for all biologics, recombinant proteins, and viral vectors derived from mammalian cell culture.
