Table 3. Prevalence of epitope variants across clades.

Th epitopes are listed in each column with clade variants listed in the rows below. The percentage frequency of each variant peptide is listed in the shaded column to the right of the peptide. These frequencies are calculated by dividing the number of sequences for each listed in the HIV database Epilign section by the total number of viruses sequenced in each clade. The total number of sequences for each clade consisted of 11 for clade A, 37 for clade B, 17 for clade C, 5 for clade D, and 11 for clade AE. The epitope EPRGSDIAGT was lengthened by one amino acid at the N-terminus as the longer epitope was recognized more frequently by subjects whose Gag-specific Th responses were mapped (L. Cosimi, unpublished data)