Dengue vaccination modulates the dengue-Zika viral system via immunogenic cross-talk

A vaccine for dengue, a viral disease which is a major driver of morbidity and mortality in tropical and subtropical regions, has recently been approved by eleven countries. While vaccination has the potential to reduce disease burden, the approved vaccine faces challenges due to the interactions between the four serotypes of dengue virus (DENV1-4) and the potential interactions with Zika virus (ZIKV), a related flavivirus. In this study, we propose a mathematical model incorporating both DENV and ZIKV in order to investigate the effects of viral competition on dengue vaccine performance, the potential for change in incidence of Zika due to dengue vaccination, and the change in incidence of secondary flavivirus infections following vaccine implementation. Our model predicts that dengue vaccine performance will be modulated by the presence of ZIKV and that dengue vaccination could lead to an increase in incidence of Zika secondary to dengue. Additionally, we predict vaccination before the introduction of ZIKV has the potential to cause future increases in incidence of secondary dengue. Our study highlights the importance of understanding the interplay between DENV and ZIKV for policy decisions regarding the implementation of the dengue vaccine