Rabbit Anti-SIV P27 Polyclonal antibody for WB. Simian immunodeficiency virus (SIV), also known as African Green Monkey virus, is a retrovirus able to infect at least 33 species of African primates. Based on analysis of strains found in four species of monkeys from Bioko Island, which was isolated from the mainland by rising sea levels about 11,000 years ago, it has been concluded that SIV has been present in monkeys and apes for at least 32,000 years, and probably much longer.