Efforts to deliver therapeutic genes are frequently rebuffed by the body's
adaptive immune response against viral delivery vectors. Attempts to circum
vent this problem using non-viral delivery systems have encountered problem
s with transient expression and inflammatory responses induced by reaction
of the innate immune system reacting against bacterial DNA. However, within
the past decade, these barriers to non-viral DNA delivery have been recogn
ized as potential allies in the development of novel vaccines for cancer an
d infectious disease. This review summarizes preclinical and current clinic
al studies testing the formulation, delivery route and adjuvant options in
the development of novel DNA-based vaccines.