WHO: Initiative for Vaccine Research (IVR)
Dengue vaccine research
Dengue is a mosquito-borne flavivirus disease that has spread to most tropical and many subtropical areas. The disease is caused by four closely related viruses, the Dengue viruses 1-4. There are no specific dengue therapeutics and prevention is currently limited to vector control measures. A dengue vaccine would therefore represent a major advance in the control of the disease.

Status of vaccine development
While no licensed dengue vaccine is available, several vaccine candidates are currently being evaluated in clinical studies.

The candidate currently at the most advanced clinical development stage, a live-attenuated tetravalent vaccine based on chimeric yellow fever-dengue virus (CYD-TDV), has progressed to phase III efficacy studies. Results from a phase IIb efficacy study in Thailand have been published in September 2012.
More information on the phase IIb study of CYD-TDV (September 2012)
pdf, 55kb

Several other live-attenuated vaccines, as well as subunit, DNA and purified inactivated vaccine candidates, are at earlier stages of clinical development. Additional technological approaches, such as virus-vectored and VLP-based vaccines, are under evaluation in preclinical studies…

http://www.who.int/vaccine_research/diseases/dengue/dengue_vaccines/en/index.html