The United States Pharmacopeia launched new standards aimed at harmonizing quality attributes for viral vectors and plasmid DNA to support the growing cell and gene therapy field. USP collaborated with NIST and NIIMBL on methods to measure AAV empty‑to‑full ratios and issued new guidance for plasmid DNA quality as a starting point for broader viral‑vector chapters. Stakeholders said the standards will reduce inter‑lab variability, help regulators and manufacturers benchmark analytics, and accelerate product comparability across the rapidly expanding pipeline. USP plans additional chapters covering lentivirus and CAR‑T manufacturing best practices and will finalize documents following public comment. Clarification: 'Empty‑full ratio' measures the proportion of viral particles that package the therapeutic genome versus empty capsids, a key quality attribute for AAV products.