The New York Times has an article on the war on dengue fever, and how the US Army is committed to the development of a vaccine because dengue affects American soldiers.
Many tropical diseases receive considerably less attention than diseases that afflict the developed countries. Research done on dengue fever is more an exception than the rule for tropical diseases. In many cases, this is because developing drugs for tropical diseases is not profitable. This is largely because consumers in countries where tropical diseases are endemic usually cannot afford expensive pharmaceuticals. This is related to the problem of orphan drugs, which the Bill and Melinda Gates foundation has started to tackle in recent years.
The interesting thing is that climate change might turn this situation around, though not because of particularly desirable reasons. Climate change and global warming will expand the warm areas around the equator poleward such that tropical diseases and their vectors will afflict the more temperate regions of today. Both Italy and Canada have experienced tropical diseases in recent years.
When the problems of the developing world become the problems of the developed world, it will almost guarantee the greater availability of research funding for tropical diseases.
Singapore is funding some efforts in this area, via the Novartis Institute for Tropical Diseases.
The Sanofi vaccine mentioned in the New York Times article is probably a DNA vaccine, an example of a new generation of vaccine technologies.