The major risks for gene therapy include:
A.
Gene therapy can trigger the immune response in the patient, that could be harmful to them. Retroviruses has raised skepticism about their safety. Deactivated viruses are really deactivated?
B.
Viral vectors may cause toxicity, infection, inflammation, etc.
C.
Gene therapy may cause off-target effects — there is a risk that the new gene will insert itself into the path of another gene, disrupting its activity, or cause insertional mutagenesis.
D.
Gene therapy may cause chronic granulomatous disease and cancer.