The invention provides, inter alia, compositions useful for, e.g., raising an immune response to HIV-1, and associated methods of raising an immune response to HIV in a mammalian subject. In some embodiments, the compositions are bivalent immunogenic compositions comprising two (or, in some embodiments more than two) human immunodeficiency virus (HIV) clade C envelope gp120 polypeptide antigens, together with a liposome-based adjuvant, such as the adjuvant known as AS01.