CD8A and lymphopenia: Despite CD3+ lymphopenia, individuals with CLL and Allo-HSCT showed levels of CD8+ T cells that were increased about 2.0-fold in both cases, before (p = 0.0038 and p = 0.0023, respectively) and after (p = 0.0018 and p = 0.0238, respectively) vaccination (Figure 5B, left graph).