(A-B) C57BL/6 mice were primed with Ad26 (109 vp) and boosted with Ad5 (109 vp) in combination with RMD, IBET151, RMD+IBET151 or PBS/DMSO. (A) Frequency and number of Gag-specific CD8 T cells in the blood. (B) Frequency of Gag-specific IFN-γ+ CD8 T cells in the spleen. (C) Experimental outline of B16-OVA challenge. (D) Tumor area measurements following B16-OVA tumor injection into primed mice and during therapeutic vaccination treatments. Each dot represents an individual mouse. n = 4–10 per group per experiment. Data are presented as means ± SEM. *p < 0.05, **p < 0.01, ***p < 0.001, Student T-test.