Proceedings of the 2023 Viral Clearance Symposium, Session 3: 2023 VCS New Modalities in Chromatography and Adsorptive Filters.

The session provided an update on the application and mechanistic understanding of intensified unit operations (e.g., mixed mode depth filters, mixed mode AEX) since the last conference in 2019. One of the key gaps identified in the 2019 Viral Clearance Symposium session on the topic was for more investigation required to achieve a clear understanding of the molecular mechanisms of virus removal and the relevance of different moleculés interactions including resin, virus, and product. Further investigation into worst-case conditions for these unit operations is also warranted. One of the key outcomes from that 2019 discussion was also that multimodal anion exchangers can have robust and effective virus removal, depending on process and impurities-an observation that was recapitulated with more specific case studies and evidenced by broader application of these chromatographic resins in late-stage regulatory filings.