One study [42] showed that there was no statistical difference between Yiqi-yangyin granules and no intervention in improving the percentage of CD8 T lymphocytes during COVID-19 recovery (MD = 1.11 scores, 95%CI -2.91 to 5.13 scores, P = 0.59, 60 participants, 1 trial) (Table 4). Here, CD8A is linked to COVID-19.