There is no attrition of preexisting memory CD8⁺ T cells after primary EBV infection. (A) Panels show data from four individual subjects depicting the total number of CD8⁺ T cells per milliliter of blood that stained with the indicated tetramers for EBV (black diamond), Flu (red circle), or CMV (blue inverted triangle) over time. Dotted lines indicate that EBV-specific T cells were not detectable before primary infection. (B) The fold expansion of CMV- and Flu-specific CD8⁺ T cells in subjects that displayed a more activated phenotype (based on >30% expression of CD38 and DR) or less activated phenotype (1–30% expression of CD38 and DR). Student’s t test, P < 0.05 (n = 26). Horizontal bars indicate the mean. (C) Flu- and CMV-specific CD8⁺ T cell numbers before and >150 d after primary EBV infection. Paired Student’s t test, P > 0.05 (n = 10 for Flu and n = 11 for CMV). Error bars indicate standard deviation.