Gene therapy experts at Nationwide Children’s Hospital have made significant advancements in designing optimal viral vectors for producing Good Manufacturing Practice (GMP)-grade viral vector products. Our experts have optimized properties of vectors for a wide variety of Adeno-associated virus (AAV) serotypes, including AAV1, 2, 2.5, 3, 5, 6, 8, 9 and rh74. In particular, our experts have optimized virus packaging efficiency, reduced potential to form replication competent AAV and replaced the beta-lactam resistant gene with kanamycin in order to be compliant with European Union (EU) regulations. Our experts have made additional optimized vectors for AAVrh74, and AAV9 that allow for more efficient purification and improved CNS transduction, respectively.