This parasite, carried by a sandfly, kills tens of thousands pf people every year. Treatment exists, but the sickness can still disfigure and kill people.
The vaccine has shown partial success in immunizing young children against the disease.
Nearly 100 million children are infected with tuberculosis, which causes 2 million deaths each year.
The U.N. has accepted partial responsibility in Haiti's 2010 cholera crisis.
Global health ranks third below terrorism and climate change in a list of public concerns.
For developing nations, more people can exacerbate current problems.