Administration of convalescent plasma may be of clinical benefit for treatment of severe acute viral respiratory infections. However, no clear evidence exists to support or oppose convalescent plasma use in clinical practice. We conducted a systematic review and meta-analysis to assess the evidence of randomized controlled trials (RCTs) in the convalescent plasma for the treatment of severe influenza.

Viral pneumonia is a major cause of morbidity and mortality around the world (1, 2). The causative organisms for viral pneumonia vary greatly. The emergence of severe acute respiratory syndrome coronaviruses (SARS-CoV) (3), avian influenza A (H5N1) virus (4) and the Middle East respiratory syndrome coronaviruses (MERSCoV) (5) played an important role as the causes of severe pneumonia successively. And now attention is turning to a novel coronavirus (SARS-CoV-2). Since December 2019, an increasing number of cases of pneumonia infected by SARS-CoV-2 have been reported in China (6-8). Up to our knowledge, there was no effective antiviral for the infection. The current approach to clinical management was general supportive care, provided with critical care and organ support when necessary. It has been suggested that administration of high-titre anti-influenza immune plasma, derived from convalescent or immunised individuals, may yield a clinical effect for treatment of seasonal and pandemic influenza of viral etiology (9-11). It was reported that convalescent plasma treatment reduced the hospital stay and mortality in patients with SARS-CoV infection and severe influenza A (H1N1) (9, 12). Furthermore, systematic reviews of studies using convalescent plasma also found evidence of clinical benefit for such patients (9, 13). Therefore, convalescent plasma may be promising in patients with SARS-CoV-2 infection (COVID-19), particularly in those presented with critical illness. However, the underlying evidence based on previous studies was of poor quality because few of them was randomized trial. And recently, randomized controlled trials had shown that convalescent plasma or hyperimmune intravenous immunoglobulin (H-IVIG) prepared from pooled plasma obtained from convalescent patients conferred no significant benefit over placebo for patients with influenza infection (14, 15), which was contrast to the previous studies. Therefore, we conducted a systematic review and meta-analysis to evaluate the clinical efficacy of either convalescent plasma or hyperimmune immunoglobulin for the treatment of severe influenza, to help inform clinical management of SARS-CoV2 infection.

Thanks and Regards,

Alpine

Associate Editor

Journal of Clinical Trials

clinicaltrials@eclinicalsci.com