Table 1.

DNA vaccines main features.

	Advantage	Drawback
Design	Allowing the introduction of several immunological components; synthetic and PCR methods for simple modifications	Low transfection efficiency
Manufacture	Rapid production and formulation; easily engineered, reproducible, large-scale production and isolation
Safety	No pathogenic infection in vivo; no significant adverse events in any clinical trial; neutralizing immune responses rarely observed; boost strategy is possible
Stability	Long shelf life; relative temperature insensitivity; lack necessity of a cold chain stored on a large scale
Immunogenicity		Lower immunogeni-city in larger animals and human compared to mice