Table 2.

Summary of the advantages and disadvantages of therapeutic HPV DNA vaccines

Advantage	Attribute of therapeutic HPV DNA vaccines
Design	• Generates effective CTL and antibody responses
	• Can express tumor antigenic peptides
	• Prolonged antigen expression increases the chances of developing immunologic memory
	• Expressed antigens are subjected to the same glycosylation and post-translational modifications as natural viral infections
Safety	• Will not revert to virulent form
	• Does not contain actual infectious agents
	• Repeated administration is safe and effective
	• Clinical trials have not shown adverse events
Stability	• Temperature-stable
	• Long shelf life
Manufacture	• High purity large scale production
	• Rapid production and formulation
	• Easy to store and transport

Disadvantage	Attribute
Specificity	• Low transfection efficiency
	• Low immunogenicity
	• DNA is unable to amplify or spread intercellularly
	• Not specifically targeted to APCs
Body reaction	• Possibility for immune responses generated against DNA
	• Risk of genomic integration

APCs, antigen-presenting cells; CTL, cytotoxic T lymphocyte.