Dynamics of susceptibility and transmissibility of the live, attenuated, candidate vaccines dengue-1 PDK13, dengue-3 PGMK30F3, and dengue-4 PDK48 after oral infection in Aedes aegypti

Dengue-1 virus PDK13 and isolates from vaccinees (dengue-l Ib1 and dengue-l Ib 10), dengue-3 PGMK30F3, and dengue-4 PDK48 were studied for their abili ties to infect, disseminate, and replicate in Aedes aegypti mosquitoes by t he oral route. In general, infection and dissemination rates were poorer fo r the vaccine compared with the parent viruses; The transmissibility was al so lower for dengue-l PDK13 than the parent virus, whereas it was not detec ted for isolates from vaccinees and dengue-3 PGMK30F3. Transmissibility of dengue-4 PDK48 was not determined because no dissemination occurred. Replic ation rates of vaccine strains were also found to be less efficient than th e parent viruses. These imply that vaccination with the candidate vaccine i s safe. Moreover, vector attenuation of vaccine viruses was consistent with its phenotypic markers of attenuation, which remained stable after a mosqu ito passage or after human and mosquito passage.