While newly identified SIVagmVer strains naturally infecting vervets from South Africa exhibited a high genetic diversity, with average genetic distances in the pol gene of 16.2±4.8%, phylogenetic analyses also identified SIVagm strains that differed in less than 2% of their pol and env nucleotide sequences, indicating epidemiologically linked infections (Figure 2 and Figure S1). The gene discussed is ERVW-1; the disease is infection.