RESUMO
The objective of the study was to evaluate if the antibodies elicited after immunization with a tetravalent dengue vaccine, based on chimeric yellow fever 17D/dengue viruses, can neutralize a large range of dengue viruses (DENV). A panel of 82 DENVs was developed from viruses collected primarily during the last decade in 30 countries and included the four serotypes and the majority of existing genotypes. Viruses were isolated and minimally amplified before evaluation against a tetravalent polyclonal serum generated during vaccine preclinical evaluation in monkey, a model in which protection efficacy of this vaccine has been previously demonstrated (Guirakhoo et al., 2004). Neutralization was observed across all the DENV serotypes, genotypes, geographical origins and isolation years. These data indicate that antibodies elicited after immunization with this dengue vaccine candidate should widely protect against infection with contemporary DENV lineages circulating in endemic countries.
Assuntos
Anticorpos Neutralizantes/sangue , Anticorpos Antivirais/sangue , Vacinas contra Dengue/imunologia , Vírus da Dengue/imunologia , Portadores de Fármacos , Vetores Genéticos , Vírus da Febre Amarela/genética , Animais , Linhagem Celular , Chlorocebus aethiops , Vacinas contra Dengue/administração & dosagem , Vacinas contra Dengue/genética , Vírus da Dengue/genética , Genótipo , Macaca fascicularis , Testes de Neutralização , Vacinas Sintéticas/administração & dosagem , Vacinas Sintéticas/genética , Vacinas Sintéticas/imunologiaRESUMO
Interferences between different antigens in the same vaccine formulation have been reported for some vaccines (e.g., polio vaccines, live attenuated dengue vaccine candidates). We examined interferences between the four serotypes of ChimeriVax dengue vaccines (CYDs) in a monkey model when present within a tetravalent formulation in equal concentrations (TV-5555). Immunoassays of vaccinated non-human primates showed that serotype 4 (DEN-4), and to a lesser extent, DEN-1 were dominant in terms of neutralizing antibody levels. Parameters that affected the interferences were identified, including 1) the simultaneous administration of two complementary bivalent vaccines at separate anatomical sites drained by different lymph nodes; 2) the sequential administration of two complementary bivalent vaccines; 3) the establishment of heterologous flavivirus pre-immunity before subsequent tetravalent immunization; 4) the adaptation of formulations by decreasing the dose of the immunodominant serotype; and 5) the administration of a 1-year booster. The applicability of these data to human responses is discussed.
