CD8A and infection: In order to assess the impact of ageing on cellular immunity, we determined the numbers of γHV68-specific CD8 T cells present in latently-infected mice at different timepoints after infection using MHC class I tetramers specific for two well-characterized γHV68 epitopes p56 (ORF6487-495) and p79 (ORF61524-531)(Figure 3).