Table 3.

This table presents the characteristics of each reviewed viral vector in the first 4 columns. In the next three columns, generalized ratings are given regarding the vectors’ performance in vivo. These ratings are somewhat subjective and are taken both from the authors’ own experience and from cited review papers. Given that the vector platforms are continuously improving, some of the vector performance ratings may change over time.

Vector	Deletions	Cell Specificity	Molecular Fate	Transgene Capacity	Immune Response in the CNS	In vivo transgene expression	Safety Concerns
rAd
First generation r-Ad	E1a, E1b, E3	neurons, glia	episomal	~8kb	High Antigenicity	high protein production variable durability pending promoter and immune response	High Toxicity
Gutless “high capacity”	All structural genes	neurons, glia	episomal	<37kb		variable protein production long-term	Toxicity dependent on titer
rAAV
rAAV1–10	rep, cap	neurons	episomal/integrated	~4.7kb	Potential antigenicity due to capsid proteins	high protein production long-term	Insertional Mutagenesis?/immune response
rHSV
replication-defective	ICP4, ICP22, ICP27, ICP47	neurons, glia	episomal/latent	~20kb	Moderate Antigenicity	high protein production short term	Moderate Toxicity
Am plicon
	All except oris and pac	neurons, glia	episomal/latent	~20kb	Low Antigenicity	low protein production short-term	Low Toxicity
rLV
1st generation rLV	vif, vpr, vpu, nef	neurons*	integrated	~9kb	low	high protein production long term	potential problems from VSV-g, pseudotyped envelope, possible HIV sero-conversion, possible recombination
2st generation rLV	vif, vpr, vpu, nef	neurons*	integrated	~9kb	low	high protein production long term	potential problems from VSV-g, pseudotyped envelope, possible HIV sero-conversion, possible recombination
3rd generation rLV	vif, vpr, vpu, nef tat, rev	neurons*	integrated	~9kb	Moderate Antigenicity	high protein production long term	VSV-g, seroconversion, recombination
Self-Inactivating	All above and 5′ LTR inactivation	neurons*	integrated	~9kb	Low Antigenicity	high protein production long term	VSV-g, seroconversion