Influenza vaccine has historically been produced in embryonated chicken eggs. However, to meet the needs for pandemic preparedness and the scalability of vaccine production, cell-based processes are now being developed and implemented in the industry. The methods for purification processes have typically involved a combination of sucrose density gradient ultracentrifugation, ultrafiltration/diafiltration (UF/DF) with hollow-fiber membranes, and chromatography using affinity, ion-exchange, and/or gel filtration media (resins). In these processes, both sucrose density gradient ultracentrifugation and gel filtration have…