Intravenous immunoglobulin (IVIG), a pooled normal IgG from several thousand healthy donors and one of the commonly used immunotherapeutic molecules for the management of autoimmune and inflammatory diseases, has been explored for the treatment of coronavirus disease-19 (COVID-19). Although placebo-controlled, double-blind randomised clinical trials are lacking, current data from either retrospective, case series or open-label randomised controlled trials provide an indicator that IVIG immunotherapy could benefit severe and critically ill COVID-19 patients. See alsoShao et al.