Human immunodeficiency virus type 1 ( HIV-1 ) has infected more than 40 million people worldwide , mainly in sub - Saharan Africa .
The high prevalence of HIV-1 subtype C in southern Africa necessitates the development of cheap , effective vaccines .
Human immunodeficiency virus type 1 ( HIV-1 ) has infected more than 40 million people worldwide , mainly in sub - Saharan Africa .
The high prevalence of HIV-1 subtype C in southern Africa necessitates the development of cheap , effective vaccines .