- a variable retrovirus that invades and inactivates helper T cells of the immune system and is a cause of AIDS and AIDS-related complex: variants were identified in several laboratories and independently named lymphadenopathy-associated virus (LAV ), human T-cell lymphotropic virus type 3 (HTLV-3 ), and AIDS-related virus (ARV ), the name human immunodeficiency virus (HIV ) being subsequently proposed by an international taxonomy committee.
