Neutralization capacity of pre-membrane and envelope antibody response of dengue serotype-1 DNA vaccine against homotypic and heterotypic dengue viruses

Dengue virus (DENV) infection is still a burden in tropical countries such as Indonesia. Although approved dengue vaccine is now currently avail-able, high viral dispersity and variety still remain challenges for vaccine efficacy. A DNA vaccine was developed based on pre-membrane and envelope (prME) gene of dengue serotype-1 (DENV-1) genotype-1 isolated from dengue patient during a dengue outbreak in Jakarta in 2009. PrME DENV-1 genes were inserted into pUMVC4, a mammalian expression vector, producing pUMVC RDS 59/09 recombinant DNA vaccine, followed by antigen expression by immunostaining. Individual mouse serum from immunized mice was tested for antibody response and pooled sera were analyzed using a focus reduction neutralization test (FRNT) to assess neutralizing antibody capacity against homotypic and heterotypic DENV-1 isolates. ELISA indicated induction of antibody levels and high FRNT₅₀ values of neutralizing antibodies were also obtained against homotypic DENV-1 genotype-1 and heterotypic genotype-4. The results show DENV DNA vaccine was promis-ing approach, which merits further development as a dengue vaccine prototype.