HIV/AIDS Glossary

A subgroup of genetically related HIV-1 viruses. HIV-1 can be classified into four groups: M group, N group, O group, and P group. Viruses within each group can be further classified by subtype. For example, the HIV-1 M group includes the following subtypes: A1, A2, A3, A4, A6, B, C, D, F1, F2, G, H, J, and K.