Dengue is a mosquito-borne flavivirus disease found mostly in tropical and some subtropical areas. It is caused by four related viruses. To date, there is no specific treatment for the disease and prevention is limited to vector control measures.
The quest for a dengue vaccine has been ongoing since 1929 but because of incomplete knowledge about the disease and the complication of targeting all four dengue serotypes, development of an effective vaccine has proven to be quite difficult.
Although you can get vaccinated from other diseases in our New York travel medicine clinic, there is no licensed vaccine available for dengue yet. It is believed that a vaccine would play a major role in controlling this disease and could help the World Health Organization achieve its goal of reducing dengue morbidity by at least 20 percent and mortality by 50 percent by 2020.
However, there are some vaccine candidates that are currently under development. Sanofi Pasteur is developing a live attenuated tetravalent dengue vaccine which is currently is a Phase III trial. The Phase III trial has been conducted to assess the safety and efficacy of the vaccine in preventing dengue for one year after completion of three doses of vaccine that are given six months apart.
The trial is expected to continue for four additional years but the results of the trial from Asia and Latin America have been reported. Vaccine efficacy against dengue serotypes has been estimated at 60.8 percent. Efficacy was found to be more effective in participants who had measurable antibodies.
Another vaccine candidate is being developed at Mahidol University in Bangkok. It is a recombinant chimeric vaccine with Phase I and Phase II trials ongoing in the US, Columbia, Puerto Rico, Singapore and Thailand. Glaxo Smith Kline in collaboration with the Walter Reed Army Institute of Research is also working on a synergistic formulation that is currently being evaluated in a Phase II study.
Merck in studying recombinant vaccines and their research in in Phase I as of 2015. In addition, the Naval Medical Research Center is developing a monovalent DNA plasmid vaccine but it has been found to be moderately immunogenic. Other vaccines in Indian and Vietnam are also under development but nothing has been commercially introduced.
While development efforts for an effective and safe dengue vaccine continue, the WHO continues to focus on identifying gaps and research needs related to this development effort. It is also engaged in building scientific guidelines that could aid this development and has also outlined strategies on vaccine implemented and introduction. It is hoped that development efforts will produce positive results soon and provide the world a therapeutic solution for this disease.