Characteristics of gene therapy vectors (adapted from Curiel et al64)
| Vector | DNA carrying capacity | Cell range | In vivo gene delivery efficiency | Duration of expression | Co-transfer viral gene elements | Inflammatory response |
| Retrovirus | <5 kb | Replicating cells only | Low | Stable | Yes | Low |
| Adenovirus | 7–8 kb | Most cells | Moderate | Transient | Yes | High |
| Adeno-associated virus | 6–7 kb | Most cells | Low | Stable | Yes | Low |
| Liposomes | >10 kb | Most cells | Low | Transient | No | Low |
| Molecular conjugates | >10 kb | Most cells | Low | Transient | No | Low |