Table 1.

Advantages and disadvantages of different gene therapy vectors

Vector	Advantages	Disadvantages
Viral vectors
Adeno-associated Viruses	Low immunogenicity Stable transgene expression	Small transgene insert capacity (~4.8 kb) Complex process of vector production
Adenovirus	Biologically safe Large transgene insert capacity (~38 kb)	High immunogenicity Short term gene expression
Herpes simplex virus	Large transgene insert capacity (~150 kb)	Immunogenicity
Lentivirus	Infect both dividing and nondividing cells Long term stable expression of transgene Low immunogenicity	Insertional mutagenesis
Measles Virus	Better safety profile	Wild type virus is immunosuppressive Many adults are immune
Retrovirus	Infect only dividing cells Stable transgene expression	Risk of insertion Small transgene insert capacity Immunogenicity, low efficiency in vivo
Vaccinia virus	Large insert capacity Better safety profile	High immunogenicity Replication in skin lesion
Vesicular Stomatitis virus	Selective replication competent in tumor cells	High immunogenicity Animal pathogen-safety concern
Non viral vectors
Plasmid/Naked DNA	Easy to engineer Low immunogenicity	Rapid clearance, low transfection efficiency
Cationic liposomes	Large gene carrying capacity Better accumulation of nanoparticle in tumors	Low transfection efficacy and inflammatory toxicity