How To Select The Right Viral Vector For Your Unique Therapy

Viral vector selection is one of the most consequential decisions in gene therapy development, yet it's often made without a full picture of the tradeoffs involved. Your choice directly shapes the safety profile, manufacturing complexity, and clinical viability of your program before a single patient is treated.

Adeno-associated virus (AAV) dominates current programs, accounting for roughly 48% of gene therapy clinical trials, and its low immunogenicity and ability to transduce both dividing and non-dividing cells explain why. But AAV's packaging capacity tops out at about 4.7 kbp, which rules it out for larger transgenes. Lentiviral vectors (LV), with stable integrating expression and an 8 kbp capacity, are the workhorses of CAR-T and other ex vivo oncology applications. Meanwhile, herpes simplex virus (HSV) is gaining ground for neurological conditions, where its 150 kbp capacity and broad cell tropism offer options that other vectors simply can't match.

Manufacturing considerations add another layer. Cleanroom grade requirements, suite segregation, staff expertise in aseptic processing, and scalability all vary by vector type. What works for AAV in suspension culture won't necessarily translate to an adherence-based retroviral process.

Download the full comparison to map each vector's characteristics against your specific therapeutic target, expression requirements, and manufacturing constraints before committing to a platform.