Figure 1: Vaccine-induced NP-specific CD8+ T cell responses in young (left) and aged C57Bl/5 female mice (right) in response to vaccination. Groups of young mice (6–8 weeks, ) and aged mice (>18 months, ) were vaccinated with 1010 vp of AdC68NP, given IM. They were bled 2, 4, 6, and 8 weeks after vaccination. PBMCs were isolated and stained with an NP-specific tetramer and antibodies to CD8 to identify the frequency of NP-specific CD8+ T cells. A portion of AdC68NP-primed mice were then boosted with 0.8 × 105 TCID50 of A/X31, along with age-matched groups of previously naïve mice.