Polyvalent, primary isolate nucleic acid compositions for inducing an immune response against HIV are disclosed. The compositions and methods described herein are for the use of a nucleic acid composition that encodes one or more different HIV envelope glycoproteins. The synthetic, codon-optimized DNAs encoding one or more HIV proteins are a combination of different nucleic acids, such as DNA plasmids, generated from primary isolate DNA of different HIV major group genetic clades and/or different proteins. HIV polypeptide compositions for inducing an immune response against HIV are also disclosed. Methods for using the polypeptide compositions before, at the same time as, and/or after administration of the DNA compositions are provided.
