Impact of age and herpesvirus infections on effector memory and naive T-cell counts. Correlation between effector memory CD8+ and CD4+(a), and naive CD8+(b) and CD4+(c) T-cell absolute counts and age according to the number of infections with herpesviruses (n = 13, 32, 39 and 49 for 0, 1, 2, and 3+ infections). Statistical significance was determined by Spearman's rank correlation. Spearman's R and p values are shown for each panel.