Fig. 2. Commonly used viral vectors for gene delivery.

AAVs are single-stranded DNA viruses with no envelope and small size that are not pathogenic to humans. The gutted Adenoviral vectors are double-strand DNA viruses devoid of most genes from their wild-type, although still capable of transducing a broad spectrum of both dividing and non-dividing cells with a capacity of carrying genetic cargo up to 35 kb. Lentiviral vectors, primarily derived from HIV-1, are capable of integrating their transgene (~9 kb) into the human genome and are suitable for long-term gene expression.