Figure 3. HCV-specific interferon-γ responses detectable in peripheral blood 2 wk following immunization. IFNγ ELIspot assays were performed on NHP PBMCs isolated at baseline and 2 wk post-immunization regimen (PIR) by stimulating cells overnight with antigen-matched overlapping linear peptide pools. HCV-specific IFNγ responses, as spot-forming units (IFNγ+ cells)/million PBMCs, are represented as stacked responses, demonstrating specificity across multiple regions of multiple antigens for individual NHPs.