The Gates Foundation invested hundreds of millions of dollars in research on neglected tropical diseases — a group of 20 parasitic and bacterial infections affecting over one billion people in the world's poorest communities, including schistosomiasis, river blindness, lymphatic filariasis, and soil-transmitted helminths. Because these diseases carry almost no commercial drug development incentive, Foundation funding was critical to supporting new drug candidates, mass drug administration campaigns, and vector control programs. By 2023 the Foundation's NTD programs had helped reduce the burden of river blindness and lymphatic filariasis dramatically across sub-Saharan Africa.