IFNγ secretion of cells from Ad5 immune mice vaccinated with heterologous and homologous prime boost regimens utilizing Ad4-CSP and Ad5-CSP. All vaccinations were capable of stimulating significantly more IFNγ secreting cells than unvaccinated and Ad5-CSP/Ad5-CSP vaccinated Ad5 immune animals. Splenocytes were collected 14 days after final vaccination. Splenocytes were then stimulated with CSP dominant antigen NYDNAGTNL and IFNγ secretion was measure by ELISpot. 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.