Battle against COVID-19: Efficacy of Convalescent Plasma as an emergency therapy

Abstract

Battle against COVID-19: Efficacy of Convalescent Plasma as an emergency therapyTo the editor:Convalescent Plasma (CP) is a form of adaptive immunization. It is an indirect way to protect a susceptible individual by providing immunity against a specific pathogen. Currently, the outbreak of highly infectious respiratory illness, i.e., novel coronavirus (COVID-19), has so far affected 2,471,136 individuals and has caused 169,006 deaths (WHO situation report-93; April 22, 2020). The USA alone reported 695,353 infected cases with the highest number of fatalities (n = 37,602). The outbreak is so dangerous that it has affected the entire world (213 countries/ areas/territories). So far, scientists are struggling to develop an effective treatment strategy. The only preventive measures rely on supportive care, quarantine, and isolation of infected patients. CP therapy was effective during the outbreaks of SARS in 2002/2003, H1N1 in 2009, and MERS in 2012. CP transfusion improves clinical symptoms and reduces the mortality rate [4]. A previous exploratory study on SARS and severe influenza performed in 2014, which included 32 separate studies, identified a reduction in mortality rate after CP transfusion. The study showed pooled odds of mortality reduced after CP therapy compared to the placebo or no treatment (OR, 0.25; 95% CI, 0.14-0.45; I2 = 0%) [5]. A retrospective nonrandomized study on 19 SARS infected patients showed reduced mortality as well as shorter hospital stay after CP transfusion [6].Similarly, a meta-analysis study on 1703 Spanish influenza pneumonia patients reported improved clinical symptoms and reduction in mortality upon CP transfusion. Absolute mortality risk range between the groups (treatment vs. control) was 8% -26% with a pooled difference of 21% [CI 95%: 15-27%] [7]. A 2015-16 MERS study on Marmosets, treated with mAb and CP, reported a reduction in clinical symptoms and viral load in the CP group [8]. During the Ebola outbreak, CP therapy was found to be effective [9,10], especially during the early phase of the epidemic and showed improved survival odds ratio (OR: 2.3; 95% CI: 0.8-6.5) [9].Phylogenetic and molecular sequencing-based studies suggest the similarity between the present COVID-19 virus and previously reported SARS and MERS viruses. Therefore, CP transfusion could be an effective therapy against COVID-19 (Table 1). Recently published article on ten American Journal of Emergency Medicine xxx (xxxx) xxx YAJEM-159069; No of Pages 3 [13]

Determination of the Concentration of IgG against the Spike Receptor-Binding Domain That Predicts the Viral Neutralizing Activity of Convalescent Plasma and Serum against SARS-CoV-2

“…As an alternative to synthetic and natural antiviral drugs, passive immunization has been used since early 20th century to treat different viral infections including SARS-CoV and MERS [ 17 , 18 ]. This old form of immunotherapy has emerged as one of the most promising treatments for severe/critical COVID-19.…”

A rapid review of recent advances in diagnosis, treatment and vaccination for COVID-19

“…The proposed mechanisms of action of convalescent plasma in COVID-19 are immune-mediated suppression of viremia by neutralization, inflammatory response modification by cytokines, antibody-dependent cellular cytotoxicity, complement activation, and phagocytosis (ADCP). The non-immune mechanism is involved in the restoration of coagulation factors [39] , [40] .…”

Convalescent Plasma: An Evidence-Based Old Therapy to Treat Novel Coronavirus Patients

“…This IgG competes with the angiotensin-converting enzyme-2 receptor (ACE-2) to bind with the virus receptor-binding domain (RBD) and may neutralize the nCoV-2019 infection. Therefore, in this case, the binding domain acts as both, i.e., the epitope for antibody and a binding site for the receptor enzyme [2]. Literature suggests that when CP therapy is administered at an early stage of nCoV-2019 infection, the therapeutic effect may be more effective [47].…”

“…Convalescent plasma (CP) is defined as a blood plasma that is withdrawn from an individual who had encountered some infectious disease and had recovered with a required amount of antibodies against the disease [1]. It is a way of passive immunization [2]. The concept has been widely used in medical sciences, especially in the case of infectious disease outbreaks.…”