They were used as experimental animals to find a suitable vaccine against hepatitis B. Now the rejected chimpanzees live on six secluded river islands in West African Liberia in order not to infect any of their free-living conspecifics.
The procedure is the same every day. Employees of the Liberia Chimpanzee Rescue Project (LCR) load a boat with fruits and vegetables. Then they head for six small islands in succession, located in the West African state of Liberia near the town of Charlesville in the Farmington River. They are already expected there: There are chimpanzees on the shore, and the LCR men throw them the food.
They wear white laboratory clothing, as the primates are used to it. After all, they were experimental animals in a research programme called "Vilab", which was carried out at the Institute for Biomedical Research in Liberia on behalf of the New York Blood Center (NYBC). The NYBC supplies blood to numerous clinics and other medical facilities in the United States.