CP and COVID-19: Some reports have shown that plasma therapy can effectively reduce the symptoms and mortality of patients with SARS-CoV-2 infection when there is no specific treatment for COVID-19 [3, 12, 13], and CP transfusion has shown good safety results in hospitalized patients with COVID-19 [14]; however, the mechanism of action of CP is not fully understood, as factors such as antibody functional activity [15, 16], antibody specificity, affinity, and host immune features, including endogenous antibody levels, may influence its effectiveness.