Clinical Staging of HIV Infection (39)a
| HIV STAGE | DEFINITION | |
| 1 | No immunosuppression (based on CD4 values) and no history of AIDS-defining illness | |
| 2 | Moderate immunosuppression (based on CD4 values) and no history of AIDS-defining illness | |
| 3 | Severe immunosuppression (based on CD4 values) or history of AIDS-defining illness | |
HIV=human immunodeficiency virus.
↵a Until 2014, CD4-based immunosuppression (none, moderate, severe) was categorized separately from a clinical staging in children (<13 years old): N, no signs or symptoms; A, mild signs or symptoms; B, moderate signs or symptoms; C, severe, AIDS-defining illness.(40)