Human Immunodeficiency Virus 2 (HIV-2) is an enveloped, spherical ssRNA retrovirus with a genome size of 9 kb. It is closely related to HIV-1, but less virulent and mainly localized to West Africa. It is transmitted through sexual contact, blood, and breastfeeding. Like HIV-1, its glycoproteins gp120 and gp41 are used to recognize CD4 receptors and fuse into host T-lymphocytes, macrophages, and dendritic cells.