Ad4-CSP/Ad5-CSP heterologous prime boost results in improved quality of T cell response. A prime injection of 1 × 1010 vp/mouse Ad4-CSP followed by a boost of 1 × 1010 vp/mouse of Ad5-CSP resulted in significantly more IFNγ secretion by splenocytes measured by ELISpot (A) and CD3+ CD8+ T cells measured by flow cytometry (B). Ad4-CSP/Ad5-CSP was the only treatment to stimulate a significantly higher percentage of TNFα production as compared to unvaccinated animals (C). Cells were stained with CD3-APC-Cy7, CD8-Alexa flour700, TNFα-PE-Cy7, IFNγ-FITC, and Granzyme B-APC. Bars represent ± standard error. Statistical analysis was completed using One Way ANOVA with Student-Newman-Keuls post-hoc test, *, **, *** denotes significance over naïve, P < 0.05, P < 0.01, P < 0.001.