Challenges in downstream purification of gene therapy viral vectors

The diversity and application of viral products has continued to explode. These modalities can be vaccines, cancer therapies, and gene therapies. However, their diversity is also the challenge in the downstream processing. Viral particles can be very labile, thus requiring intimate knowledge of biology to create environments where they are stable. However, despite these challenges, we have created many processes that produce large amounts of viral products. Different purification methods are utilized throughout the process. New modalities of chromatography are overcoming many of the challenges of diffusion-limited beads. Of special concern for gene therapy vectors is the need to separate the empty capsids from the full capsids, which contain the therapeutic gene of interest. With the discovery of novel therapuetic modalities that could revolutionize care by finding cures, the downstream processing of viral therapies needs to find solutions to make these therapies and cures affordable.