CP and COVID-19: Despite these limitations, this study provided more evidence to support that CP therapy might be a promising option to treat COVID-19 patients, which is also supported by the recent issue by FDA of emergency use authorization for CP as potential promising COVID-19 treatment.31 Overall, this study not only provided more evidence on the potential efficacy and safety of CP therapy, but also contributed to the quality control of donated plasma and reasonable clinical application of CP transfusion.