Table 1. Comparison of the Main Properties, Advantages and Disadvantages of Commonly Used Viral Vectors^a.

vector type	packaging capacity	diameter	genome type	advantages	disadvantages	current examples
AAV	<4.4 kB	20–22 nm	ssDNA	large variety of target tissues, low immunogenicity on first injection	low packaging capacity	(16)
AV	>8 kB	80–100 nm	dsDNA	large packaging capacity, transient Cas expression	pre-existing antibodies, high immunogenicity	(17)
LV	<8.5 kB	80–120 nm	ssRNA	large packaging capacity	potential insertional mutagenesis	(18−21)

^aReferences of current examples are given for future reading.