Design and delivery of non-parenteral vaccines

Non-parenteral delivery of vaccines is reviewed focusing on the delivery systems that have been used for various mucosal routes of administration. Systems considered include biodegradable micro- and nanoparticles, liposomes, live bacterial and viral vectors and mucosal adjuvants. New approaches to mucosal vaccine formulation using: (i) gene fusion technology to create non-toxic derivatives of mucosal adjuvants, (ii) genetically inactivated antigens with a deletion in an essential gene, (iii) coexpression of an antigen and a specific cytokine that is important in the modulation and control of a mucosal immune response, and (iv) genetic material itself that would allow DNA or RNA uptake and its endogenous expression in the host cell are described.