The Flaviviridae family includes the largest number of arthropod-borne-viruses which are pathogenic for humans and cause serious public health problems. Effective vaccines exist for three of them: yellow fever, Japanese encephalitis and tick-borne encephalitis. The first is attenuated and the others are inactivated virus preparations. Although dengue represents the most important mosquito-borne viral disease, no vaccine is readily available. The construction of future dengue vaccines based on the recognition of target proteins, the characterization of their structural organization, the identification of immunogenic elements and on the definition of B- and T-cell epitopes, is discussed in this report. The research model for designing recombinant vaccines produced by genetic engineering is discussed for viruses in general and for dengue in particular.