Abstract: Embodiments of the invention provide processes for the selection of HIV-1 subtype (clade) C isolates, selected HIV-1 subtype C isolates, their genes and modifications and derivatives thereof for use in prophylactic and therapeutic vaccines to produce proteins and polypeptides for the purpose of eliciting protection against HIV infection or disease. A process for the selection of HIV subtype isolates comprises the steps of isolating viruses from recently infected subjects; generating a consensus sequence for at least part of at least one HIV gene by identifying the most common codon or amino acid among the isolated viruses; and selecting the isolated virus or viruses with a high sequence identity to the consensus sequence. HIV-1 subtype C isolates, designated Du422, Du 151 and Du 179 (assigned Accession Numbers 01032114, 00072724 and 00072725, respectively, by the European Collection of Cell Cultures) are also provided.