Dengue: a growing threat requiring vaccine development for disease prevention.

Dengue disease is the most prevalent mosquito-borne viral infection in humans. At least one half of the global population is estimated at risk of infection and an estimated 390 million people are infected each year. Over the past few years, dengue burden continued to increase, mainly impacting developing countries. Alarming changes in dengue epidemiology were observed highlighting a spread from tropical to subtropical regions as well as urban to rural areas. An increase in the co-infections with the four serotypes has also been noticed, involving a shift in the targeted population from pediatric to adult. Facing these global changes, authorities will have to reinforce preventive actions and adapt healthcare management. New prophylactic strategies are urgently needed to prevent severe forms of dengue disease. The lack of specific antiviral therapies available turns vaccine development into a socio-economic challenge. In this review, we propose an update on the dengue global trends and different vaccine strategies in development. A particular attention will be paid to up-to-date information on dengue transmission and the protective efficacy of newly commercialized tetravalent dengue vaccine Dengvaxia®, as well as the most advanced candidate vaccines in clinical development.