Fig. 5: Heterologous vectors boost Ad26 vaccine–induced cellular immune responses in the presence of pre-existing Ad26 immunity in cynomolgus macaques.

IFNγ ELISpot responses in PBMC were determined as described in the Fig. 3 legend, with peptide pools for EBOV GP (a, b); SUDV GP (c); and HIV Env, Gag, and Pol (d). Shown are background-subtracted values per animal of animals receiving an Ad26/Ad26 (a) or Ad26/Ad35 (b) regimen encoding EBOV GP; Ad26 encoding SUDV GP and MVA encoding SUDV GP, EBOV GP, MARV GP (c); or Ad26/MVA encoding Env, Gag, and Pol of HIV (d). Animals that had received an Ad26 vaccine during the A-series are annotated as Ad26/Ad26rep (a), Ad26/Ad35rep (b), or Ad26/MVArep (c, d). In (a–d), the dotted line represents the assay threshold of 50 SFU/10⁶ PBMC. In (e), the fold-change is depicted and corresponds to the change in responses comparing pre–dose 2 to peak response post–dose 2 per animal. Ad26/Xrep refers to animals vaccinated in the A-series, and Ad26/X refers to animals that were not vaccinated during the A-series. The red horizonal line is the geometric mean. Pairwise comparison of the difference between pre-exposed animals and unexposed animals per time point was performed for data in (a–d), summarized in Supplementary Table 1. An ANOVA was performed over the fold-changes per study and across the 3 studies over the data shown in (e), summarized in Supplementary Table 3.