DNA vaccines against infectious agents: recent strategies for enhancing immune responses

Abstract

Background: There have been widespread efforts to develop plasmid DNA vaccines against animal and human pathogens. The impetus stemmed from early promising results in laboratory animals in which DNA vaccines induced robust immune responses and, in some cases, protection against challenge. However, first-generation DNA vaccines did not induce optimal responses in larger animals and humans. Objective: To examine technological developments in DNA plasmids, adjuvants, and delivery systems. Methods: The advancements that have been made in DNA vaccines for infectious diseases are reviewed and some historical perspective is provided. Results/conclusions: Although improvements in DNA vaccine technology have been realized, it is evident that this progress has resulted in rather modest improvements in responses in large animals and humans.

Keywords::

• adjuvants
• delivery systems
• plasmid DNA
• vaccine