Vaccine research for dengue was started in the 1940s by Sabin and colleagues. There have been several attempts to make a successful vaccine but this objective has not been realized. We know a lot about virus and disease, but no vaccine has been developed that is approved for use till now.
The complexity of dengue vaccine development
There are several problems in making a successful dengue vaccine.
- Dengue is caused by four related types of dengue virus (designated as DEN-1, DEN-2, DEN-3 and DEN-4). For a vaccine to be successful it should induce immunity against all four viruses concurrently.
- Infection with any type of dengue virus leads to lifelong protective immunity against that particular type of infecting virus (homotypic immunity). However, a secondary infection with any type of dengue virus (e.g. DEN-1 followed by DEN-4) can cause severe and even fatal dengue infection. Hence a major concern is that---will the vaccination lead to potential severe dengue if strong immunity is not developed against all four viruses.
Currently a vaccine is undergoing clinical trial in the USA which will protect against all four dengue viruses, DENV-1, DENV-2, DENV-3 and DENV-4. But the safety and effectiveness of the vaccine remains to be proven.
Read articles and Understand dengue