DNA Vaccine Expressing Mature Dengue Virus-Like Particles and Serological Tests to Distinguish Dengue and Zika.

Abstract

Our study investigated DNA vaccines expressing mature dengue virus (DENV) viruslike particles (VLPs) and developed serological tests to distinguish dengue and Zika. We showed that human-codon optimized DNA vaccines improved the expression and production of VLPs in vitro compared with non-codon optimized DNA vaccines. Human-codon optimized DNA vaccine expressing mature VLPs induced similar level of anti-DENV and neutralizing antibodies compared with that expressing mixed VLPs. Secondly, we found that DNA-prime and inactivated virion-boost regimens improved the immunogenicity in mice compared with DNA vaccine alone. Future challenge experiments are needed to show the protective effect of these vaccine candidates. Thirdly, we demonstrated that combination of three enzyme-linked immunosorbent assays based on non-structural protein 1 can distinguish DENV and Zika virus infections with high specificity and sensitivity. In light of the cross-reactivity of current serological tests, our findings have implications for serodiagnosis between DENV and Zika virus or other flaviviral infections.