The Human Dengue Challenge Experience at the Walter Reed Army Institute of Research

Recent discordance between measured levels of serotypes of dengue virus neutralizing antibody and clinical outcomes suggests a need to reevaluate the process of prescreening dengue vaccine candidates to better predict their clinical benefit before initiation of large-scale human vaccine trials. In the absence of a reliable animal model for dengue, a human dengue virus challenge model (ie, a controlled live dengue virus infectious challenge study) may prove useful and timely to elucidate mechanisms that underlie protection (as well as virulence), thus facilitating down-selection of vaccine candidates before beginning advanced field trials. Dengue challenge stud-ies were safely used in prior decades to study the vector biology, clinical spectrum of illness, and reactogenicity of candidate live dengue virus vaccines of uncertain attenuation. Redeveloping the human dengue challenge model following current regulatory guidance, good manufacturing practice, and good clinical practice could streamline and accelerate vaccine development by offering a time- and resource-efficient method to evaluate the safety and potential efficacy of dengue vaccine and therapeutic candidates. In this article, the development of such a challenge model and its subsequent application is summarized from 2 recent reports