Human immunodeficiency virus
(Science: virology) a type of retrovirus (human immunodeficiency virus) that is responsible for the fatal illness acquired immunodeficiency syndrome. Two strains have been identified.
type 1: the retrovirus recognised as the agent that induces aids.
type 2: a virus closely related to hiv-1 that also leads to immune suppression. Hiv-2 is not as virulent as hiv-1 and is epidemic only in west Africa.
The virus that causes acquired Immune Deficiency Syndrome (aids); it replicates in and kills the helper t cells.