ABSTRACT
The development and planning of a viral clearance study, as stipulated in the guidance documents, is related to the potential for viruses to enter the production system from either the cell line or other sources such as raw materials [1-6]. The International Conference on Harmonization (ICH) Q5A, in fact, ranks cell lines based on the presence of viral particles or viruses [7]. This stratiŒcation of the cell line will then determine the viral clearance that needs to be demonstrated. Other documents written by the Food and Drug Administration (FDA) or the European authorities provide general guidance and in some cases details on the design and implementation of viral clearance studies.
