We employed vaccinia virus as a vector to express the three structural proteins, capsid(c), membrane (M) or its precursors PreM, and envelope glycoprotein (E), as well as the nonstructural protein NS1 from a 5'-terminal fragment of cloned dengue virus DNA. We observed that the three dengue virus glycoproteins, PreM, E, and NS1 were produced in recombinant vaccinia virus-infected cells and their glycosylation pattern was similar to that observed during dengue virus infection. Infection of cotton rats with the vaccina virus recombinant induced a poor immune response to the NS1 glycoprotein, while antibodies for the other two glycoproteins were not detected at all. Nevertheless, mice immunized with this vaccina virus recombinant developed complete resistance to fatal dengue encephalitis.
