Immunization with electroporation enhances the protective effect of a DNA vaccine candidate expressing prME antigen against dengue virus serotype 2 infection

•pVAX1-D2ME via electroporation induced strong humoral and cellular immunity in mice.•pVAX1-D2ME via electroporation immunization elicited effective protection in mice.•High IgG and NAb titer were gained in DNA-immunized rabbits via electroporation.•Electroporation is more effective to delivery DNA than intramuscular injection.

PurposeWe aimed to use the dengue virus (DV) serotype 2 as a proof of principal for testing the efficacy of a DNA vaccine candidate via in vivo electroporation in mice and rabbits prior to the development of a tetravalent vaccine.MethodsDifferent dosages of DNA pVAX1-D2ME encoding DV2 prME genes were vaccinated in mice via intramuscular injection or in vivo electroporation, immune responses and protection were determined. In DNA-vaccinated rabbits via electroporation, antibody titer and protein expression were tested.ResultsIn mice, 50 μg of pVAX1-D2ME via electroporation elicited effective anti-DV2 responses and conferred significant protection against DV2 challenge. Moreover, anti-DV2 IgG and neutralizing antibodies were successfully induced in rabbits immunized with pVAX1-D2ME via electroporation and the expression of the interest protein was observed at local sites.ConclusionsEnhanced immunogenicity and protective effect conferred by pVAX1-D2ME via electroporation show great promise for the development of a dengue tetravalent DNA vaccine.