Simian Immunodeficiency Virus

Simian Immunodeficiency Virus (SIV) is a clade of lentivirus that infects primate CD4 cells. SIV can infect at least 33 different nonhuman primate species. SIV can also jump from nonhuman primates to humans and establish new clades. When this happens, the new clade is renamed "Human Immunodeficiency virus" (HIV). SIV is endemic to more than thirty African primate species. Numerous nonhuman primate lentiviruses have been discovered. Many SIVs grow in vitro in human cells.