The effects of Annual SZ drug on dynamic changes in lymphocytes and cytokines of COVID-19 patients: A randomized clinical trial

•Annual SZ syrup contains artemisinin and its derivatives.•Annual SZ increased T lymphocytes frequency in the treatment of COVID-19 patients.•Exhausted T cell marker (PD-1) less increased during the treatment by Annual SZ.•Annual SZ decreased the inflammatory response against SARS-COV-2 in COVID-19 patients.•Oxygen saturation of COVID-19 patients improved during the treatment by Annual SZ. The search for a potent anti-coronavirus therapy has remained an overwhelming task since the outbreak of COVID-19. Annual SZ is a novel formulation of artemisinin and its derivatives. We aim to investigate the effect of Annual SZ on clinical outcomes, cellular immune responses, and cytokine changes in COVID-19 patients. This study included 80 COVID-19 hospitalized patients, which were randomly allocated into two groups (intervention and control). Both groups received standard supportive treatment. In addition, the intervention group (n = 40) received Annual SZ syrup, and the control group (n = 40) received a placebo. Dynamic changes in lymphocytes, cytokines, and clinical status were evaluated since hospital admission to 7 and 14 days after treatment. The dynamic count of total T lymphocytes and T lymphocyte subsets (CD4+ and CD8+) in the Annual SZ group was significantly higher than the placebo group (p