Patients with infections after HSCT did not reach the thresholds defined for CD3+-cells significantly later than those without infections, however, we found a significant difference for the threshold of > 10% CD4+CD45RA+-cells (p = 0.014): While patients without viral infections reached the threshold with a median time of 102.0 days (IQR = 114), those with infections reached it at a median time of 154.0 days (IQR = 166). Here, CD4 is linked to infection.