[Tetravalent dengue vaccine development]

The Sanofi Pasteur tetravalent dengue vaccine candidate (TV) is composed of four recombinant live attenuated vaccines based on a yellow fever virus vaccine 17D (YFV 17D) backbone, each expressing the prM and envelope genes of one of the four dengue virus serotypes. Pre-clinical studies have demonstrated that the TV dengue vaccine is genetically and phenotypi- cally stable, non-hepatotropic, less neurovirulent than YFV 17D and does not infect mosquitoes by the oral route. In clinics, TV dengue vaccine reactogeni- city, viraemia induction and antibody responses were investigated in three Phase II trials in endemic and non-endemic countries, which demonstrated its good safety and immunogenicity. An extensive clinical development program for dengue TV is underway including an efficacy trial in Thailand, in an area of high dengue incidence. Assuming continued successful outcomes, initial submissions to regulatory authorities are envisaged within a 5-year period.