INTRODUCTION
As of 17 March 2020, China had been informed of 81116 confirmed cases of coronavirus disease 2019 (COVID-19), of whom 3231(3.98%) have died. Until now, the virus still spread and have not been fully controlled[1]. The treatment of COVID-19 was mainly general supportive therapy[2]. Recently,It had been suggested that Convalescent plasma therapy will yield a clinical effect for the treatment of severe patients expecialy with cytokine storm[3].However, The effectiveness were not yet verified, the underlying evidence is based on studies of other viral infections including Middle East respiratory syndrome coronavirus (MERS-CoV) and Severe Acute Respiratory Syndrome coronavirus (SARS-CoV)[4].We conducted a systematic review and meta-analysis to evaluate the clinical effectiveness of convalescent plasma for the treatment of MERS-CoV and SARS-CoV , to help inform clinical management of COVID-19.
2. Material and Methods
2.1 We searched the databases containing PubMed, and Google scholar.We used the following keywords: “2019 Novel coronavirus” or “2019 novel coronavirus infection” or “COVID19” or “coronavirus disease 2019” or “coronavirus disease-19” or “2019-nCoV disease” or “2019 novel coronavirus disease” or “2019-nCoV infection” or “Wuhanvirus” or “coronavirus” or “SARS” or “MERS” AND “convalescent plasma” or “ Blood Plasma” “Blood Fresh Frozen Plasma” or “Frozen Plasma, Fresh” or “Plasma, Fresh Frozen”.
2.2 The inclusive and exclusive criteria
2.2.1 Inclusive criteria: studies that include randomized controlled trials, non-randomized controlled trials, and patients in hospital or sent to the Intensive Care Unit (ICU) for treatment.
2.2.2 Exclusive criteria: repeated articles; reviews;studies on animals or In vitro studies.
2.2.3 paper quality evaluation
Two members of the team evalued the quality using the Newcastle-Ottawa Scale (NOS).
2.2.4 Statistical analysis
All statistical analyses were carried out with  RevMan5.3 (Cochrane ), Statistical significance was assumed at the 5% level.
3. Results
An initial search identified a total of 35 articles from PubMed, 615 from Google scholor. After reviewing for inclusion and exclusion and the removal of duplications, a total of 7 studies were used for the full review (Figure 1). The mortality from the 7 trials showed convalescent plasma for the treatment of patients with Coronavirus was associated with lower mortality (odds ratio [OR]=0.27;95% confidence interval [CI]=0.15-0.50; Figure 2). Visual inspection of a funnel plot, did not exclude publication bias (Figure 3).