在gene therapy、病毒和non-viral vectors are used to deliver atherapeutic geneto a patient's cells.

Viruses are the perfect tool for nucleic acid delivery as they naturally evolved to bring in their genetic material into cells to replicate. Some viruses, such asretroviruses, even insert their genes into the host cells genome. In order to ensure the safety of the viral vectors, either the whole viral genome is replaced by the therapeutic gene or the parts that are disease-causing are deleted from the viral vector.

Different types of viral vectors exist:

• Adenoviruses
• Aden-associated virus (AAV)
• Retrovirus
• Herpes Simplex Virus
• Vaccinia Virus

Figure 1:在corporation of a therapeutic gene into the viral vector adeno-associated virus (AAV).