A viral vector is a genetically engineered virus that has been modified to deliver therapeutic genetic material into target cells while retaining its natural ability to infect and introduce nucleic acids into the host cell, but rendered replication-incompetent to ensure biosafety. The most widely used viral vectors in gene therapy and cell therapy include adeno-associated virus (AAV), adenoviral vectors, lentiviral vectors (LVV), and retroviral vectors, each offering distinct profiles of tissue tropism, cargo capacity, immunogenicity, integration behavior, and manufacturing scalability. Their GMP production requires highly specialized upstream and downstream manufacturing processes, analytical characterization, and regulatory expertise, making viral vector manufacturing one of the most complex and high-value services offered by CDMOs.
