Table 3.

Summary of characteristics of vectors used for glutamic acid decarboxylase expression in pain treatment (modulated from the report⁵)

	HSV	AV	AAV vector	FV vector
Wild type	DS-DNA	DS-DNA	SS-DNA	a
Genome size (kb)	152	36	∼4.7	13
Capacity of gene inserted (kb)	∼40	∼7.5	∼4.5	9.2
Persistence of gene expression	Days–weeks	Days–weeks	Months–years	Days–weeks
Safety issues	Immune and inflammatory response	Immune and inflammatory response	Insertional mutagenesis	Apathogenicb

^aThe relative amount of RNA and DNA in FV virions is still debated.⁹⁹

^bInduced a marked cytopathic effect at a high multiplicity of infection in vitro.⁹⁹

AAV, adeno-associated virus; AV, adenoviral vector; FV, foamy virus; HSV, herpes simplex virus.