Developing a vaccine against dengue is challenging. With four closely related viruses that can cause the disease, the vaccine must immunize against all four types to be effective. There is also limited understanding of how the disease typically behaves and how the virus interacts with the immune system, as well as a lack of laboratory animal models available to test immune responses to potential vaccines. Despite current efforts to control dengue, based primarily on vector control and case management, the burden and costs of the disease remain considerable. Vector control will continue to be an important piece of controlling dengue, but it is clear that a vaccine is also needed.
Substantial progress towards finding a vaccine has been made in the last decade. Several vaccines are in various stages of advanced development, with clinical trials currently underway on five candidate vaccines. Trials in the most advanced stages are showing encouraging preliminary data. A range of different vaccines are being explored, including live attenuated vaccines, live chimeric virus vaccines and live recombinant, DNA and subunit vaccines. Each type comes with its own unique challenges and benefits but, to date, live attenuated vaccines have been the most researched and successful.