Broad neutralization of wild-type dengue virus isolates following immunization in monkeys with a tetravalent dengue vaccine based on chimeric Yellow Fever 17D/Dengue viruses

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.

► Context: Tetravalent chimeric dengue vaccine has entered phase III trials.
► Study aim: Evaluation of breath of neutralization among same serotype’ strains.
► Tested viruses: Representative panel.
► Eighty circulating dengue virus strains.
► Major result: Antibodies elicited in vaccinated monkeys neutralize all strains.
► Conclusion: Large breath of protection expected in humans.