According to the World Health Organisation, Leishmaniasis, a chronic and sometimes deadly skin disease, is a growing problem which affects the poorest of the poor.
The disease, found in places like the Middle East and South America, is commonly linked to malnutrition, poor housing, and a lack of resources.
There are currently around 15 million cases of Leishmaniasis around the world, with 1.5 to 2 million new cases being diagnosed every year.
But, a vaccine could be on the way, thanks to two unlikely US researchers - and a prestigious science prize.
Al Jazeera's Kimberly Halkett reports from Washington.