Interferon gamma (IFN-γ) T-cell responses to nanovaccine formulations at Day 28. C57BL/6 mice were immunized twice, two weeks apart, intradermally at the base of the tail with the following formulations; PBS alone (Naïve), OVA alone, OVA + CpG-PEG-b-PLGA NPs, OVA-PS NPs, OVA-PS NPs + CpG-PEG-b-PLGA NPs, OVA-PEG-b-PLGA NPs, or OVA-PEG-b-PLGA NPs + CpG-PEG-b-PLGA NPs. All animals received 50 µg OVA. CpG-PEG-b-PLGA NP groups received 5 µg CpG. Graph shows IFN-γ T-cell responses to (A) whole OVA, (B) CD8+ T-cell epitope (SIINFEKL), and the (C) CD4+ T-helper OVA epitope (ISQAVHAAHAEINEAGR) by ELISpot assay. Individual mice are shown for each recall antigen ± experimental error from triplicate assay wells.