Fig 1.

IFN-γ ELISpot assays were conducted on samples from HESN from HIV-1-discordant couples and low-risk controls from concordant HIV-negative couples using 1 × 10⁵ cultured PBMC with 3 wells per peptide pool. Pools with ≥50 HIV SFU/10⁶ PBMC and >2 times the background were defined as positive responses. A response to any peptide pool covering the viral region was counted as a region response (restricted to samples with a background of <50 SFU/10⁶ PBMC). (a) T cell IFN-γ ELISpot responses by viral region. (b) Breadth of responses based on the number of viral regions to which participants mounted a response. The P values are for χ² tests comparing the distributions between groups.