Table 1.

Gene therapy vectors.

Vector	Preexisting immunity	Proliferation needed	Genome integration	Pathogenicity	Viral persistence	Specificity	Limitations (Viral titres and safety)
Adenovirus	+	−	No	+++	No	CAR receptors	+
AAV	+	−	?	No	Yes
Retrovirus	−	Yes	Yes	No	Yes		+
Lentivirus	−	−	Yes	No ?	Yes	CD4 +	+
Poxvirus	+/−	−	No	No	No
Bacterial vvectors, eg, salmonella	?	−	No	Antibiotics	No	Inflammation	?
Liposomes	−	−	No	−	−		−
Naked DNA	−	−	?	No	No