For their experiment, they absolutely cannot use humans as a sample. So they use chimpanzees as an alternative. According to the WWF (,nd), they found that chimpanzee genes have 96% to 98% similarity to humans. This is the main reason why chimpanzees were used in the experiment. For example, to find the vaccine against HIV/AIDS. So far researchers have failed to find the vaccine, but many chimpanzees have been killed because of it. Scientists know that to find something new they have to sacrifice something. Scientists focus only on finding new medicines, without thinking about the negative effects on the lives of chimpanzees. Indirectly, chimpanzees become endangered animals