HIV-1 subtype C as a major determinant of the global AIDS epidemic

Human immunodeficiency virus type 1 (HIV-1) subtype C appears to be spreadi ng more rapidly relative to other subtypes of HIV-1 and is responsible for most new infections in countries with emerging epidemics. In southern Afric a, HIV-1 seroprevalences are high and almost exclusively attributed to subt ype C infections. It is also the most dominant subtype in India and parts o f China and, although the HIV seroprevalences in these regions are lower, t he total number of infections is high.(1) It is estimated that 10 million p eople are infected with HIV-1 subtype C through heterosexual and perinatal transmission. Vaccine developers are now focusing on this subtype in an att empt to curb its continued expansion. Compared to HIV-1 subtype a, which do minates in the U.S.A. and Europe, considerably less is known about subtype C viruses, although recent data indicate that they show distinct features. This paper focuses on what is currently known about subtype C and how this might influence the global spread and design of a vaccine.