Candidate vaccines for dengue fever have not consistently conferred protective immunity against the virus, despite inducing antibody responses in clinical trials.
Researchers developing a live dengue virus vaccine, known as TV003, carried out a human challenge study. They administered the vaccine or a placebo to 41 participants who were then exposed to a strain of the virus associated with mild symptoms six months later.
The researchers found that the vaccine conferred complete protection against the dengue virus and none of the participants given TV003 developed viremia, rash or neutropenia. In contrast, 100%, 80% and 20% of participants given placebo displayed these symptoms, respectively.
Reporting in Science Translational Medicine (online, 16 March 2016)
, the researchers say that a human challenge study cannot substitute clinical efficacy trials, but could be useful in identifying promising vaccines and thereby accelerate vaccine development.
 Kirkpatrick BD, Whitehead SS, Pierce KK et al. The live attenuated dengue vaccine TV003 elicits complete protection against dengue in a human challenge model. Science Translational Medicine 2016;8:330ra36. doi: 10.1126/scitranslmed.aaf1517