Proceedings of the 2023 Viral Clearance Symposium, Session 1: Regulatory Updates.

At the time of the 2023 Viral Clearance Symposium in Vienna, the ongoing revision of ICH Guideline Q5A(R1) Viral Safety Evaluation of Biotechnology Products Derived from Cell Lines of Human or Animal Origin clearly was the dominant regulatory topic. At the symposium, the changes expected for Q5A(R2) to mirror advances of scientific knowledge, for example, the inclusion of new products, including viral-vector-derived ones, that can be subject to virus clearance, deliberations around continuous manufacturing processes, the use of prior knowledge to supplement or in part replace virus validation studies, and new molecular methods for detection of adventitious viruses, were discussed by a European and a US regulator as well as representatives from industry associations that had been involved with the drafting process.