Due to recent technological advances in gene editing and gene delivery, several gene therapy products to treat rare diseases have been approved, and many more are in various stages of clinical trials. Gene Therapies using viral vectors are perhaps the most popular with other vectors like lipid nano particles, exosomes, etc., not too far behind. The current talk provides an introduction to what gene therapies are, the different types of gene therapies and different DMPK and clinical pharmacology aspects of gene therapies. The presentation will more specifically focus on shedding and immunogenicity aspects of viral gene therapies. As host immune response plays a critical role in clearing the body of the virus, immunogenicity against the virus and the newly expressed transgene product can limit the efficacy of the administered gene therapy product and, in certain instances can cause adverse events. The presentation will parse out different aspects of immunogenicity against the gene therapy products and provide an insight into its management in the clinic.