Rachel Legmann, PhD, Repligen, Waltham, MA, describes issues in producing viral vectors and approaches to improve manufacturing capabilities. Low yield and constraints in bioreactor capacity affects a wide range of viral vectors including adeno-associated viral (AAV) vectors, lentiviral vectors, and oncolytic vectors. Additional barriers include the process of replicating viral vectors, where transfection and lysis are stages in the manufacturing process that are difficult to scale up. Viral vectors are also more difficult to produce cost effectively due to the stricter safety regulations needed. This interview took place at Advanced Therapies Week 2022.