Immunization by Application of DNA Vaccine onto a Skin Area Where the Hair Follicles Have Been Induced into Anagen-Onset Stage

The study demonstrated that applying a DNA vaccine encoding anthrax protective antigen (PA) onto skin areas where hair follicles were induced into the anagen-onset stage significantly enhanced immune responses in mice compared to areas in the telogen stage. The immunized mice produced stronger anti-PA antibodies, which enabled them to survive a lethal dose of anthrax toxin. This enhanced response was attributed to increased antigen gene expression, plasmid DNA uptake, and moderate dermal inflammation associated with anagen induction, suggesting a novel method to boost the efficacy of topically applied DNA vaccines.