Research published in mid-2013 shows that there could be five, not four, dengue serotypes. A dengue outbreak in Malaysia’s Sarawak province in 2007 was genetically distinct from the other four serotypes, according to research conducted by Nikos Vasilakis from the University of Texas. While this fifth serotype has only been linked to humans in this part of Malaysia, it is still significant, as it makes the first new dengue virus in 50 years. At the Third International Conference on Dengue and Dengue Fever, held in Bangkok in October 2013, Vasilakis claimed that while this fifth dengue serotype has not been identified outside of this Malaysian region, he suspects that it is present among macaques. It’s too early to tell whether or not this is an isolated outbreak, or whether the fifth serotype is present elsewhere.
This discovery adds a new challenge to the development of a dengue vaccine. Results from clinical trials showed that the vaccine proved effective in some dengue serotypes, but not all. And this is something that researchers, such as these academics, have attempted to explain. A fifth serotype means that – if transmitted – there could be a need for a specialized vaccine. It also means that we can’t sit still in our efforts to break dengue and that these developments intensify the need for global action against dengue fever.