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 topically onto skin areas where hair follicles were induced into the anagen-onset stage significantly enhanced the immune response in mice. This enhancement was due to increased antigen gene expression, plasmid DNA uptake, and moderate dermal inflammation. The anti-PA antibody levels were higher in the anagen-onset group compared to the telogen stage group and were comparable to intramuscular injection. Cholera toxin was necessary as an adjuvant, and a high DNA concentration was required for a detectable immune response. The study involved 5-7 female Balb/C mice per group and maintained skin integrity during the procedure.