INFECTION-ENHANCING ANTIBODY RESPONSES TO GENETIC VARIANTS OF DENGUE VIRUS SEROTYPE 2 IN HEALTHY ADULTS IN BANGKOK, THAILAND

Abstract

Dengue virus serotype 2 (DENV2) has been strongly associated with severe dengue manifestations, and its genotypic diversity may influence infection outcomes through antibody-dependent enhancement (ADE). This study aimed to preliminary detect the infection-enhancing activity of antibodies against three genotypically distinct DENV2 variants Asian I, Sylvatic, and Cosmopolitan among healthy individuals residing in Bangkok, Thailand. A total of 30 serum samples were examined of the level of infection-enhancing antibodies using a luciferase-based ADE assay against DENV2 reporter representing three genetic variants in the same conditions. The Sylvatic genotype revealed the highest ADE activity, followed by Asian I genotype, while the Cosmopolitan genotype exhibited minimal enhancement. Significant differences in ADE responses were observed across genotypes (p < 0.05). Peak enhancement was observed in age groups 30-49 years. This study highlights the role of DENV2 genotypic diversity in modulating ADE activity of population residing in dengue endemic area. The elevated enhancement response to the Sylvatic and Asian I genotype suggests increased risk for severe outcomes upon secondary infections in endemic populations. Genotype-specific functional assays can be valuable for guiding vaccine development and risk assessment strategies.