A new analysis highlights that viral contamination continues to pose a bottleneck for cell and gene therapy (CGT) quality control, with raw material testing still the foundation because existing viral inactivation and removal processes may damage sensitive cells or vectors. Japan’s Pharmaceuticals and Medical Devices Agency (PMDA) cited limits of conventional protein-therapy approaches and emphasized risk management through comprehensive screening. The report frames the challenge as both technological and regulatory: CGT products often cannot tolerate the harsh conditions used for traditional biologics manufacturing validation. As a result, screening-based strategies remain dominant, despite their limitations. For CGT developers, the key signal is that improved detection platforms—such as next-generation sequencing for adventitious virus detection—are expected to play a larger role while the field works toward gentler, vector-compatible safety solutions.