Long-term protection against dengue viruses in mice conferred by a tetravalent DNA vaccine candidate.

The development of an effective tetravalent vaccine against dengue viruses (DENVs) has become a world priority. We previously showed that four monovalent dengue DNA vaccines expressing premembrane (prM) and envelope (E) proteins displayed effective protection against corresponding challenges in mice. Thus, to elucidate the overall immunity and persistence of the tetravalent formulation (TetraME), we evaluated the humoral and cellular immune responses as well as the long-term protection in the current study.

Maternal immunization with a DNA vaccine candidate elicits specific passive protection against post-natal Zika virus infection in immunocompetent BALB/c mice.

Zika virus (ZIKV) infection is closely associated in the fetus with microcephaly and in the adults with Guillain-Barré syndrome and even male infertility. It is an urgent international priority to develop a safe and effective vaccine that offers protection to both women of childbearing age and their children. In this study, female immunocompetent BALB/c mice were immunized with a DNA-based vaccine candidate, pVAX1-ZME, expressing the prM/E protein of ZIKV, and the immunogenicity for maternal mice and the post-natal protection for suckling mice were evaluated.

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

Purpose: We 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.

Methods: Different 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.