Treatment of Coronavirus Disease 2019 (COVID-19) Patients with Convalescent Plasma

Selecting COVID-19 convalescent plasma for neutralizing antibody potency using a high-capacity SARS-CoV-2 antibody assay

BACKGROUND

Efficacy of COVID-19 convalescent plasma (CCP) is hypothesized to be associated with the concentration of neutralizing antibodies (nAb) to SARS-CoV-2. High capacity serologic assays detecting binding antibodies (bAb) have been developed; nAb assays are not adaptable to high-throughput testing. We sought to determine the effectiveness of using surrogate bAb signal-to-cutoff ratios (S/Co) in predicting nAb titers using a pseudovirus reporter viral particle neutralization (RVPN) assay.

METHODS

CCP donor serum collected by three US blood collectors was tested with a bAb assay (Ortho Clinical Diagnostics VITROS Anti-SARS-CoV-2 Total, CoV2T) and a nAb RVPN assay. Prediction effectiveness of various CoV2T S/Co criteria was evaluated for RVPN nAb NT50 titers using receiver operating characteristics.

RESULTS

Seven hundred and fifty-three CCPs were tested with median CoV2T S/Co and NT50 of 71.2 of 527.5. Proportions of donors with NT50 over target nAb titers were 86% ≥1:80, 76% ≥1:160, and 62% ≥1:320. Increasing CoV2T S/Co criterion reduced the sensitivity to predict NT50 titers, while specificity to identify those below increased. As target NT50 titers increase, the CoV2T assay becomes less accurate as a predictor with a decline in positive predictive value and rise in negative predictive value.

CONCLUSION

Selection of a clinically effective nAb titer will impact availability of CCP. Product release with CoV2T assay S/Co criterion must balance the risk of releasing products below target nAb titers with the cost of false negatives. A two-step testing scheme may be optimal, with nAb testing on CoV2T samples with S/Cos below criterion.

Convalescent plasma therapy - a silver lining for COVID-19 management?

The COVID-19 pandemic has pushed the world towards social, economic, and medical challenges. Scientific research in medicine is the only means to overcome novel and complex diseases like COVID-19. To sum up the therapeutic wild-goose chase, many available antivirals and repurposed drugs have failed to show successful clinical evidence in patient recovery, several vaccine candidates are still waiting in the trial pipelines and a few have become available to the common public for administration in record time. However, with upcoming evidence of coronavirus mutations, available vaccines may thrive on the spirit of doubt about efficacy and effectiveness towards these new strains of Severe Acute Respiratory Syndrome Coronavirus (SARS-CoV2). In all these collective uncertainties, plasma therapy has shown a ray of hope for critically ill patients. To date, with very few published case studies of convalescent plasma in COVID-19, there are two school of thought process in the scientific community regarding plasma therapy efficiency and this leads to confusion due to the lack of optimal randomized and controlled studies. Without undertaking any robust scientific studies, evidence or caution, accepting any therapy unanimously may cause more harm than good, but with a clearer understanding of SARS-CoV2 immunopathology and drug response, plasma therapy might be the silver lining against COVID-19 for the global community.

Convalescent Blood: Current Perspective on the Efficacy of a Legacy Approach in COVID-19 Treatment

Since early 2020, COVID-19 has wreaked havoc in many societies around the world. As of the present, the SARS-CoV-2-borne disease is propagating in almost all countries, affecting hundreds of thousands of people in an unprecedented way. As the name suggests, the novel coronavirus, widely known as SARS-CoV-2, is a new emerging human pathogen. A novel disease of relatively unknown origin, COVID-19 does not seem to be amenable to the currently available medicines since there is no specific cure for the disease. In the absence of any vaccine or effective antiviral medication, we have no tools at our disposal, but the method of quarantine, be it domestic or institutional, to hinder any further progression of this outbreak. However, there is a record of physicians in the past who practiced convalescent blood transfusion. To their awe, the method seemed to be useful. It is anticipated that these contemporary methods will outdo any other vaccination process in the time being, as blood transfusion is instead a cost-effective and time-friendly technique. Following a successful trial, this new approach of contemporary nature to a viral disease may serve as an emergency intervention to intercept infectious outbreaks and prevent an impending epidemic/pandemic. In this review, we document the most recent evidence regarding the efficiency of convalescent plasma and serum therapy on SARS, MERS, and particularly COVID-19, while discussing potential advantages and possible risks of such practice.

Clinical and laboratory evaluation of patients with SARS-CoV-2 pneumonia treated with high-titer convalescent plasma

Here, we report on a phase IIa study to determine the intubation rate, survival, viral clearance, and development of endogenous Abs in patients with COVID-19 pneumonia treated with convalescent plasma (CCP) containing high levels of neutralizing anti-SARS-CoV-2 Abs. Radiographic and laboratory evaluation confirmed all 51 treated patients had COVID-19 pneumonia. Fresh or frozen CCP from donors with high titers of neutralizing Abs was administered. The nonmechanically ventilated patients (n = 36) had an intubation rate of 13.9% and a 30-day survival rate of 88.9%, and the overall survival rate for a comparative group based on network data was 72.5% (1625/2241). Patients had negative nasopharyngeal swab rates of 43.8% and 73.0% on days 10 and 30, respectively. Patients mechanically ventilated had a day-30 mortality rate of 46.7%; the mortality rate for a comparative group based on network data was 71.0% (369/520). All evaluable patients were found to have neutralizing Abs on day 3 (n = 47), and all but 1 patient had Abs on days 30 and 60. The only adverse event was a mild rash. In this study on patients with COVID-19 disease, we show therapeutic use of CCP was safe and conferred transfer of Abs, while preserving endogenous immune response.

Combination of Angiotensin (1-7) Agonists and Convalescent Plasma as a New Strategy to Overcome Angiotensin Converting Enzyme 2 (ACE2) Inhibition for the Treatment of COVID-19

Coronavirus disease-2019 (COVID-19) pandemic caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is currently the most concerning health problem worldwide. SARS-CoV-2 infects cells by binding to angiotensin-converting enzyme 2 (ACE2). It is believed that the differential response to SARS-CoV-2 is correlated with the differential expression of ACE2. Several reports proposed the use of ACE2 pharmacological inhibitors and ACE2 antibodies to block viral entry. However, ACE2 inhibition is associated with lung and cardiovascular pathology and would probably increase the pathogenesis of COVID-19. Therefore, utilizing ACE2 soluble analogs to block viral entry while rescuing ACE2 activity has been proposed. Despite their protective effects, such analogs can form a circulating reservoir of the virus, thus accelerating its spread in the body. Levels of ACE2 are reduced following viral infection, possibly due to increased viral entry and lysis of ACE2 positive cells. Downregulation of ACE2/Ang (1-7) axis is associated with Ang II upregulation. Of note, while Ang (1-7) exerts protective effects on the lung and cardiovasculature, Ang II elicits pro-inflammatory and pro-fibrotic detrimental effects by binding to the angiotensin type 1 receptor (AT1R). Indeed, AT1R blockers (ARBs) can alleviate the harmful effects associated with Ang II upregulation while increasing ACE2 expression and thus the risk of viral infection. Therefore, Ang (1-7) agonists seem to be a better treatment option. Another approach is the transfusion of convalescent plasma from recovered patients with deteriorated symptoms. Indeed, this appears to be promising due to the neutralizing capacity of anti-COVID-19 antibodies. In light of these considerations, we encourage the adoption of Ang (1-7) agonists and convalescent plasma conjugated therapy for the treatment of COVID-19 patients. This therapeutic regimen is expected to be a safer choice since it possesses the proven ability to neutralize the virus while ensuring lung and cardiovascular protection through modulation of the inflammatory response.

A trend of dropping anti-SARS-CoV-2 plaque reduction neutralization test titers over time in Canadian convalescent plasma donors

BACKGROUND

Convalescent plasma products are a potential passive immunotherapy for Coronavirus disease 2019 (COVID-19) disease. Various approaches have been utilized to determine the concentration of Severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2)-neutralizing antibodies in plasma products. The Canadian Blood Services used Plaque Reduction Neutralization Test 50 (PRNT₅₀₎ -generated values to qualify convalescent plasma donations supporting clinical trials in Canada. This manuscript describes changes in PRNT₅₀ titers of repeat male plasma donations collected approximately 1-4 months after onset of COVID-19 signs and symptoms in donors.

STUDY DESIGN AND METHODS

Men were eligible to donate if they: met standard criteria, were < 67 years of age, reported a previous SARS-CoV-2-positive nucleic acid test, and recovered and were symptom free for at least 28 days prior to donation. Repeat donation analysis required at least one original and one repeat donation where a PRNT₅₀ was performed.

RESULTS

From April 29, 2020 to July 25, 2020, 156 donors donated once, with 78 (50%) of the donated plasma having PRNT₅₀ titers of ≥1:160. Thirty-seven (23.7%) of the donated plasma had a titer of 1:40 or 1:80 (individuals donating this plasma were asked to donate a second time only). A total of 30 donors (19.2%) had repeat donations. Of the repeat donors, 15 (50%) had at least an eightfold change from peak to trough PRNT₅₀ titers within greater than 90 days after onset of COVID-19 symptoms.

CONCLUSIONS

Blood operators cannot infer that SARS-CoV-2 PRNT₅₀ will remain high in repeat plasma donors 3-4 months after onset of COVID-19 symptoms.

Convalescent Plasma Antibody Levels and the Risk of Death from Covid-19

BACKGROUND

Convalescent plasma has been widely used to treat coronavirus disease 2019 (Covid-19) under the presumption that such plasma contains potentially therapeutic antibodies to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) that can be passively transferred to the plasma recipient. Whether convalescent plasma with high antibody levels rather than low antibody levels is associated with a lower risk of death is unknown.

METHODS

In a retrospective study based on a U.S. national registry, we determined the anti-SARS-CoV-2 IgG antibody levels in convalescent plasma used to treat hospitalized adults with Covid-19. The primary outcome was death within 30 days after plasma transfusion. Patients who were enrolled through July 4, 2020, and for whom data on anti-SARS-CoV-2 antibody levels in plasma transfusions and on 30-day mortality were available were included in the analysis.

RESULTS

Of the 3082 patients included in this analysis, death within 30 days after plasma transfusion occurred in 115 of 515 patients (22.3%) in the high-titer group, 549 of 2006 patients (27.4%) in the medium-titer group, and 166 of 561 patients (29.6%) in the low-titer group. The association of anti-SARS-CoV-2 antibody levels with the risk of death from Covid-19 was moderated by mechanical ventilation status. A lower risk of death within 30 days in the high-titer group than in the low-titer group was observed among patients who had not received mechanical ventilation before transfusion (relative risk, 0.66; 95% confidence interval [CI], 0.48 to 0.91), and no effect on the risk of death was observed among patients who had received mechanical ventilation (relative risk, 1.02; 95% CI, 0.78 to 1.32).

CONCLUSIONS

Among patients hospitalized with Covid-19 who were not receiving mechanical ventilation, transfusion of plasma with higher anti-SARS-CoV-2 IgG antibody levels was associated with a lower risk of death than transfusion of plasma with lower antibody levels. (Funded by the Department of Health and Human Services and others; ClinicalTrials.gov number, NCT04338360.).

Effects and Safety of Convalescent Plasma Administration in a Group of Polish Pediatric Patients with COVID-19: A Case Series

Despite the enormous advances in knowledge about the SARS-CoV-2 infection, the optimal treatment for COVID-19 is still not well defined. The use of convalescent plasma seems to be a promising method of treatment but requires further evaluation. Although it is usually mild, in children with underlying chronic diseases, the course of SARS-CoV-2 infection may be very severe. We described a series of 13 pediatric patients (mean age 10.4 years, median 12) treated with convalescent plasma as a method of COVID-19 therapy. Medical history, with particular emphasis on comorbidities, clinical course, laboratory parameters, supportive treatment and virus elimination time, were analyzed. The mean hospitalization time was 22.6 days (median 20). The most common abnormalities included increased levels of C-reactive protein, D-dimer, and lymphopenia. Median time from symptom onset to convalescent plasma transfusion was 10.6 days (median 7 days). Six patients (46.2%) had a viral clearance on RT-PCR method from a nasopharyngeal swab within 3 days of transfusion, while in the remaining patients the mean elimination time was 12.1 days (median 6 days). Clinical improvement was achieved in all patients; no adverse effects were found in any of the cases. Convalescent plasma may be a promising treatment for COVID-19 in children.

Machine Learning-Based Prediction of COVID-19 Severity and Progression to Critical Illness Using CT Imaging and Clinical Data

Objective

To develop a machine learning (ML) pipeline based on radiomics to predict Coronavirus Disease 2019 (COVID-19) severity and the future deterioration to critical illness using CT and clinical variables.

Materials and Methods

Clinical data were collected from 981 patients from a multi-institutional international cohort with real-time polymerase chain reaction-confirmed COVID-19. Radiomics features were extracted from chest CT of the patients. The data of the cohort were randomly divided into training, validation, and test sets using a 7:1:2 ratio. A ML pipeline consisting of a model to predict severity and time-to-event model to predict progression to critical illness were trained on radiomics features and clinical variables. The receiver operating characteristic area under the curve (ROC-AUC), concordance index (C-index), and time-dependent ROC-AUC were calculated to determine model performance, which was compared with consensus CT severity scores obtained by visual interpretation by radiologists.

Results

Among 981 patients with confirmed COVID-19, 274 patients developed critical illness. Radiomics features and clinical variables resulted in the best performance for the prediction of disease severity with a highest test ROC-AUC of 0.76 compared with 0.70 (0.76 vs. 0.70, p = 0.023) for visual CT severity score and clinical variables. The progression prediction model achieved a test C-index of 0.868 when it was based on the combination of CT radiomics and clinical variables compared with 0.767 when based on CT radiomics features alone (p < 0.001), 0.847 when based on clinical variables alone (p = 0.110), and 0.860 when based on the combination of visual CT severity scores and clinical variables (p = 0.549). Furthermore, the model based on the combination of CT radiomics and clinical variables achieved time-dependent ROC-AUCs of 0.897, 0.933, and 0.927 for the prediction of progression risks at 3, 5 and 7 days, respectively.

Conclusion

CT radiomics features combined with clinical variables were predictive of COVID-19 severity and progression to critical illness with fairly high accuracy.

Early Administration of Convalescent Plasma Improves Survival in Patients with Hematological Malignancies and COVID-19

The use of convalescent plasma in the treatment of COVID-19 may lead to a milder course of infection and has been associated with improved outcomes. Determining optimal treatments in high risk populations is crucial, as is the case in those with hematological malignancies. We analyzed a cohort of 23 patients with hematological malignancies and COVID-19 who had received plasma 48-72 h after the diagnosis of infection and compared it with a historical group of 22 patients who received other therapy. Overall survival in those who received convalescent plasma was significantly higher than in the historical group (p = 0.03460). The plasma-treated group also showed a significantly milder course of infection (p = 0.03807), characterized by less severe symptoms and faster recovery (p = 0.00001). In conclusion, we have demonstrated that convalescent plasma is an effective treatment and its early administration leads to clinical improvement, increased viral clearance and longer overall survival in patients with hematological malignancies and COVID-19. To our knowledge, this is the first report to analyze the efficacy of convalescent plasma in a cohort of patients with hematological malignancies.

The role of the thymus in COVID-19 disease severity: implications for antibody treatment and immunization

The thymus is a largely neglected organ but plays a significant role in the regulation of adaptive immune responses. The effect of aging on the thymus and immune senescence is well established, and the resulting inflammaging is found to be implicated in the development of many chronic diseases including atherosclerosis, hypertension and type 2 diabetes. Both aging and diseases of inflammaging are associated with severe COVID-19 disease, and a dysfunctional thymus may be a predisposing factor. In addition, insults on the thymus during childhood may lead to abnormal thymic function and may explain severe COVID-19 disease among younger individuals; therefore, measurement of thymic function may assist COVID-19 care. Those with poor thymic function may be treated prophylactically with convalescent serum or recombinant antibodies, and they may respond better to high-dose or adjuvanted COVID-19 vaccines. Treatments inducing thymic regeneration may improve patients' overall health and may be incorporated in COVID-19 management.

Pharmacotherapeutics of SARS-CoV-2 Infections

The COVID-19 pandemic has affected more than 38 million people world-wide by person to person transmission of the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Therapeutic and preventative strategies for SARS-CoV-2 remains a significant challenge. Within the past several months, effective treatment options have emerged and now include repurposed antivirals, corticosteroids and virus-specific antibodies. The latter has included convalescence plasma and monoclonal antibodies. Complete viral eradication will be achieved through an effective, safe and preventative vaccine. To now provide a comprehensive summary for each of the pharmacotherapeutics and preventative strategies being offered or soon to be developed for SARS-CoV-2.

Donor Anti-Spike Immunity is Related to Recipient Recovery and Can Predict the Efficacy of Convalescent Plasma Units

BACKGROUND

The novel coronavirus, SARS-CoV2 that causes COVID-19 has resulted in the death of more than 2.31 million people within the last year and yet no cure exists. Whereas passive immunization with COVID-19 convalescent plasma (CCP) provides a safe and viable option, selection of optimal units for therapy and lack of clear therapeutic benefit from transfusion remain as barriers to the use of CCP.

STUDY DESIGN AND METHODS

To identify plasma that is expected to benefit recipients, we measured anti-SARS-CoV2 antibody levels using clinically available serological assays and correlated with the neutralizing activity of CCP from donors. Neutralizing titer of plasma samples was measured by assaying infectivity of SARS-CoV-2 spike protein pseudotyped retrovirus particles in the presence of dilutions of plasma samples. We also used this assay to identify evidence of passive transfusion of neutralizing activity in CCP recipients.

RESULTS

Viral neutralization and anti-spike protein antibodies in 109 samples from 87 plasma donors were highly varied but modestly correlated with each other. Recipients who died of COVID-19 were found to have been transfused with units with lower anti-spike antibody levels and neutralizing activity. Passive transfer of neutralization activity was documented in 62% of antibody naive plasma recipients.

CONCLUSIONS

Since viral neutralization is the goal of CCP transfusion, our observations not only support the use of anti-spike SARS-CoV2 serology tests to identify beneficial CCP units, but also support the therapeutic value of convalescent plasma with high titers of anti-spike antibodies.

Potential mechanisms of action of convalescent plasma in COVID-19

The COVID-19 pandemic will be remembered as one of the worst catastrophic events in human history. Unfortunately, no universally recognized effective therapeutic agents are currently available for the treatment of severe SARS-CoV-2 infection. In this context, the use of convalescent plasma from recovered COVID-19 patients has gained increasing interest thanks to the initially positive clinical reports. A number of mechanisms of action have been proposed for convalescent plasma, including direct neutralization and suppression of viremia, anti-inflammatory and immunomodulation effects and mitigation of the COVID-19-associated hypercoagulable state. These immune and non-immune mechanisms will be critically discussed in this narrative review.

Perspectives for immune plasma treatment of COVID-19

Background/aim

The SARS-CoV-2 infection was declared as a pandemic by the World Health Organization (WHO) on March 11, 2020, and the death toll from COVID-19, which is the disease caused by SARS-CoV-2, has already surpassed that of many previous epidemics. A wide variety of treatment options are being considered for COVID-19, but there is still no definitive treatment or vaccine. This study aims to explain the background of convalescent plasma (CP) treatment and its relations with COVID-19 immunity, to define ideal treatment procedures, and to reveal present and future perspectives in the light of the rapidly growing data. Immunological basis of COVID-19-associated immune response and convalescent plasma as a treatment option: Since it has been shown that the impaired immune response of the host is one of the most important factors that increase the severity of the infection, treatment strategies to suppress aberrant immune activation are currently being considered. CP, which is derived from recently recovered patients and contains neutralizing antibodies and many other immune- modulatory substances, seems to be the most convenient strategy to restore normal immune function considering the fast spreading nature of the ongoing pandemic.

Conclusion

Even though mechanisms of action of plasma therapy are not fully delineated, it was shown that it could lead to a reduction in mortality since other alternatives such as monoclonal antibodies or SARS-CoV-2 hyperimmunoglobulin require much more time and effort to be developed.

Limited window for donation of convalescent plasma with high live-virus neutralizing antibody titers for COVID-19 immunotherapy

Millions of individuals who have recovered from SARS-CoV-2 infection may be eligible to participate in convalescent plasma donor programs, yet the optimal window for donating high neutralizing titer convalescent plasma for COVID-19 immunotherapy remains unknown. Here we studied the response trajectories of antibodies directed to the SARS-CoV-2 surface spike glycoprotein and in vitro SARS-CoV-2 live virus neutralizing titers (VN) in 175 convalescent donors longitudinally sampled for up to 142 days post onset of symptoms (DPO). We observed robust IgM, IgG, and viral neutralization responses to SARS-CoV-2 that persist, in the aggregate, for at least 100 DPO. However, there is a notable decline in VN titers ≥160 for convalescent plasma therapy, starting 60 DPO. The results also show that individuals 30 years of age or younger have significantly lower VN, IgG and IgM antibody titers than those in the older age groups; and individuals with greater disease severity also have significantly higher IgM and IgG antibody titers. Taken together, these findings define the optimal window for donating convalescent plasma useful for immunotherapy of COVID-19 patients and reveal important predictors of an ideal plasma donor.

Current views on the potentials of convalescent plasma therapy (CPT) as Coronavirus disease 2019 (COVID-19) treatment: A systematic review and meta-analysis based on recent studies and previous respiratory pandemics

Convalescent plasma therapy (CPT) has been investigated as a treatment for COVID-19. This review evaluates CPT in COVID-19 and other viral respiratory diseases, including severe acute respiratory syndrome (SARS), Middle East respiratory syndrome (MERS) and influenza. PubMed and Google scholar databases were used to collect eligible publications until 8 December 2020. Meta-analysis used Mantel-Haenszel risk ratio (RR) with 95% confidence interval (CI) and pooled analysis for individual patient data with inverse variance weighted average. The study is registered at PROSPERO with the number of CRD4200270579. Forty-four studies with 36,716 participants were included in the pooled analysis and 20 studies in the meta-analysis. Meta-analysis showed reduction of mortality (RR 0.57, 95% CI [0.43, 0.76], z = 3.86 [p < 0.001], I²  = 44% [p = 0.03]) and higher number of discharged patients (RR 2.53, 95% CI [1.72, 3.72], z = 4.70 [p < 0.001], I²  = 3% [p = 0.39]) in patients receiving CPT compared to standard care alone. A possible mechanism of action is prompt reduction in viral titre. Serious transfusion-related adverse events were reported to be less than 1% of cases, suggesting the overall safety of CPT; nevertheless, the number of patients participating in the studies was still limited. It is also important to notice that in all the studies, the majority of patients were also given other medications, such as antivirals, antibiotics and corticosteroid; furthermore, randomized controlled studies involving more patients and in combination with other treatment modalities are urgently needed.

Two patients with rituximab associated low gammaglobulin levels and relapsed covid-19 infections treated with convalescent plasma

Patients with haematological malignancies are considered to be a risk group for developing severe Coronavirus disease (Covid-19). Because of the limitations of therapeutic options, the development of new treatment strategies is mandatory, such as convalescent plasma (CP). Herein we report the use of CP therapy as an off-label indication in two lymphoma patients with relapsed COVID-19 in the setting of low gammaglobulin levels because of previous rituximab chemo-immunotherapy. Both were PCR positive for SARS-CoV-2 but had an absence of antibodies to the virus more than one month later of symptoms initiation. They developed important respiratory and neurological complications. After CP infusion, neutralising antibodies were detected and viral load dissapeared in both patients leading to clinical improvement with no more Covid-19 relapse.

Quantifying Absolute Neutralization Titers against SARS-CoV-2 by a Standardized Virus Neutralization Assay Allows for Cross-Cohort Comparisons of COVID-19 Sera

The global coronavirus disease 2019 (COVID-19) pandemic has mobilized efforts to develop vaccines and antibody-based therapeutics, including convalescent-phase plasma therapy, that inhibit viral entry by inducing or transferring neutralizing antibodies (nAbs) against the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) spike glycoprotein (CoV2-S). However, rigorous efficacy testing requires extensive screening with live virus under onerous biosafety level 3 (BSL3) conditions, which limits high-throughput screening of patient and vaccine sera. Myriad BSL2-compatible surrogate virus neutralization assays (VNAs) have been developed to overcome this barrier. Yet, there is marked variability between VNAs and how their results are presented, making intergroup comparisons difficult. To address these limitations, we developed a standardized VNA using CoV2-S pseudotyped particles (CoV2pp) based on vesicular stomatitis virus bearing the Renilla luciferase gene in place of its G glycoprotein (VSVΔG); this assay can be robustly produced at scale and generate accurate neutralizing titers within 18 h postinfection. Our standardized CoV2pp VNA showed a strong positive correlation with CoV2-S enzyme-linked immunosorbent assay (ELISA) results and live-virus neutralizations in confirmed convalescent-patient sera. Three independent groups subsequently validated our standardized CoV2pp VNA (n > 120). Our data (i) show that absolute 50% inhibitory concentration (absIC50), absIC80, and absIC90 values can be legitimately compared across diverse cohorts, (ii) highlight the substantial but consistent variability in neutralization potency across these cohorts, and (iii) support the use of the absIC80 as a more meaningful metric for assessing the neutralization potency of a vaccine or convalescent-phase sera. Lastly, we used our CoV2pp in a screen to identify ultrapermissive 293T clones that stably express ACE2 or ACE2 plus TMPRSS2. When these are used in combination with our CoV2pp, we can produce CoV2pp sufficient for 150,000 standardized VNAs/week.IMPORTANCE Vaccines and antibody-based therapeutics like convalescent-phase plasma therapy are premised upon inducing or transferring neutralizing antibodies that inhibit SARS-CoV-2 entry into cells. Virus neutralization assays (VNAs) for measuring neutralizing antibody titers (NATs) are an essential part of determining vaccine or therapeutic efficacy. However, such efficacy testing is limited by the inherent dangers of working with the live virus, which requires specialized high-level biocontainment facilities. We therefore developed a standardized replication-defective pseudotyped particle system that mimics the entry of live SARS-CoV-2. This tool allows for the safe and efficient measurement of NATs, determination of other forms of entry inhibition, and thorough investigation of virus entry mechanisms. Four independent labs across the globe validated our standardized VNA using diverse cohorts. We argue that a standardized and scalable assay is necessary for meaningful comparisons of the myriad of vaccines and antibody-based therapeutics becoming available. Our data provide generalizable metrics for assessing their efficacy.

Efficacy of convalescent plasma therapy for COVID-19: A systematic review and meta-analysis

The purpose of this systematic review and meta‐analysis was to examine clinical outcomes associated with convalescent plasma therapy in COVID‐19 patients. We performed a literature search on PubMed, medRxiv, Web of Science, and Scopus to identify studies published up to December 10th, 2020 that examined the efficacy of convalescent plasma treatment for COVID‐19. The primary endpoints were mortality, clinical improvement, and hospital length of stay. We screened 859 studies that met the search criteria, performed full‐text reviews of 56 articles, and identified 15 articles that fulfilled inclusion criteria for meta‐analysis. The odds of mortality were significantly lower in the convalescent plasma group compared to the control group (OR = 0.59 [95% CI = 0.44; 0.78], P < .001), although results from two key randomized controlled trials did not support the mortality benefit. The odds of clinical improvement were significantly higher in the convalescent plasma group compared to the control group (OR = 2.02 [95% CI = 1.54; 2.65], P < .001). There was no difference in hospital length of stay between the convalescent plasma group and the control group (MD = −0.49 days [95% CI = −3.11; 2.12], P = .713). In all, these data indicate that a mortality benefit with convalescent plasma is unclear, although there remain benefits with convalescent plasma therapy for COVID‐19.

Therapeutic Strategies in the Management of COVID-19

Since December 2019, SARS-CoV-2 (COVID-19), novel corona virus has caused pandemic globally, with rise in the number of cases and death of the patients. Vast majority of the countries that are dealing with rise in the active cases and death of patients suffering from novel corona viruses COVID-19 are trying to content the virus by isolating the patients and treating them with the approved antiviral that have been previously used in treating SARS, MERS, and drugs that are used to treat other viral infections. Some of these are under clinical trials. At present there are no therapeutically effective antiviral present and there are no vaccines or drugs available that are clinically approved for treating the corona virus. The current strategy is to re-purpose the available drugs or antiviral that can minimise or reduce the burden of the health care emergencies. In this article the reuse of antiviral, US-FDA approved drugs, plant based therapeutic, anti-malarial, anti-parasitic, anti-HIV drugs and the traditional medicines that are being currently used in treating the symptoms of COVID-19 patients is discussed emphasis is also given on the treatment using monoclonal antibodies. The present article provides the therapeutic strategies that will qualify as one of the best available treatment for the better management of the COVID-19 patients in order to achieve medical benefits.

Convalescent plasma may be a possible treatment for COVID-19: A systematic review

INTRODUCTION

The coronavirus disease 2019 (COVID-19) pandemic has spread globally. Therapeutic options including antivirals, anti-inflammatory compounds, and vaccines are still under study. Convalescent plasma(CP) immunotherapy was an effective method for fighting against similar viral infections such as SARS-CoV, and MERS-CoV. In the epidemic of COVID-19, a large number of literatures reported the application of CP. However, there is controversy over the efficacy of CP therapy for COVID-19. This systematic review was designed to evaluate the existing evidence and experience related to CP immunotherapy for COVID-19.

METHODS

A literature search was conducted on Pubmed, Cochrane Library, Clinical Key, Wanfang Database; China National Knowledge Infrastructure(CNKI) were used to search for the proper keywords such as SARS-CoV-2, COVID-19, plasma, serum, immunoglobulins, blood transfusion, convalescent, novel coronavirus, immune and the related words for publications published until 15.10.2020. Other available resources were also used to identify relevant articles. The present systematic review was performed based on PRISMA protocol. Data extraction and risk of bias assessments were performed by two reviewers.

RESULTS

Based on the inclusions and exclusions criteria, 45 articles were included in the final review. First, meta-analysis results of RCTs showed that, there were no statistically significant differences between CP transfusion and the control group in terms of reducing mortality(OR 0.79, 95% CI 0.52-1.19, I2 = 28%) and improving clinical symptoms(OR 1.21, 95%CI 0.68-2.16; I2 = 0%). The results of controlled NRSIs showed that CP therapy may reduce mortality in COVID-19 patients(RR 0.59, 95% CI 0.53-0.66, I2 = 0%). Second, limited safety data suggested that CP is a well-tolerated therapy with a low incidence of adverse events. But, due to lack of safety data for the control group, it is really not easy to determine whether CP transfusion has an impact on moderate to serious AEs. Thirdly, for children, pregnant, elderly, tumor and immunocompromised patients, CP may be a well-tolerated therapy, if the disease cannot be controlled and continues to progress. Studies were commonly of low or very low quality.

CONCLUSIONS

Although the results of limited RCTs showed that CP cannot significantly reduce mortality, some non-RCTs and case report(series) have found that CP may help patients improve clinical symptoms, clear the virus, and reduce mortality, especially for patients with COVID-19 within ten days of illness. We speculate that CP may be a possible treatment option. High-quality studies are needed for establishing stronger quality of evidence and pharmacists should also be actively involved in the CP treatment process and provide close pharmaceutical care.

COVID-19: Imbalanced Immune Responses and Potential Immunotherapies

The ongoing pandemic coronavirus disease 2019 (COVID-19) caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is rapidly spreading and has resulted in grievous morbidity and mortality worldwide. Despite the high infectiousness of SARS-CoV-2, the majority of infected individuals are asymptomatic or have mild symptoms and could eventually recover as a result of their balanced immune function. On the contrary, immuno-compromised patients are prone to progress into severe or critical types underpinned by the entanglement of an overexuberant proinflammatory response and injured immune function. Therefore, well-coordinated innate and adaptive immune systems are pivotal to viral eradication and tissue repair. An in-depth understanding of the immunological processes underlying COVID-19 could facilitate rapidly identifying and choosing optimal immunotherapy for patients with severe SARS-CoV-2 infection. In this review, based on current immunological evidence, we describe potential immune mechanisms and discuss promising immunotherapies for COVID-19, including IL-6R blockades, convalescent plasma, intravenous gamma globulin, thymosin alpha1, corticosteroids, and type-I interferon, and recent advances in the development of COVID-19 vaccines.

Distinct Features and Functions of Systemic and Mucosal Humoral Immunity Among SARS-CoV-2 Convalescent Individuals

Understanding humoral immune responses to SARS-CoV-2 infection will play a critical role in the development of vaccines and antibody-based interventions. We report systemic and mucosal antibody responses in convalescent individuals who experienced varying severity of disease. Whereas assessment of neutralization and antibody-mediated effector functions revealed polyfunctional antibody responses in serum, only robust neutralization and phagocytosis were apparent in nasal wash samples. Serum neutralization and effector functions correlated with systemic SARS-CoV-2-specific IgG response magnitude, while mucosal neutralization was associated with nasal SARS-CoV-2-specific IgA. Antibody depletion experiments support the mechanistic relevance of these correlations. Associations between nasal IgA responses, virus neutralization at the mucosa, and less severe disease suggest the importance of assessing mucosal immunity in larger natural infection cohorts. Further characterization of antibody responses at the portal of entry may define their ability to contribute to protection from infection or reduced risk of hospitalization, informing public health assessment strategies and vaccine development efforts.

Pathogenesis of Multiple Organ Injury in COVID-19 and Potential Therapeutic Strategies

Severe acute respiratory disease coronavirus 2 (SARS-CoV-2, formerly 2019-nCoV) is a novel coronavirus that has rapidly disseminated worldwide, causing the coronavirus disease 2019 (COVID-19) pandemic. As of January 6th, 2021, there were over 86 million global confirmed cases, and the disease has claimed over 1.87 million lives (a ∼2.2% case fatality rate). SARS-CoV-2 is able to infect human cells by binding its spike (S) protein to angiotensin-conversing enzyme 2 (ACE2), which is expressed abundantly in several cell types and tissues. ACE2 has extensive biological activities as a component of the renin-angiotensin-aldosterone system (RAAS) and plays a pivotal role as counter-regulator of angiotensin II (Ang II) activity by converting the latter to Ang (1-7). Virion binding to ACE2 for host cell entry leads to internalization of both via endocytosis, as well as activation of ADAM17/TACE, resulting in downregulation of ACE2 and loss of its protective actions in the lungs and other organs. Although COVID-19 was initially described as a purely respiratory disease, it is now known that infected individuals can rapidly progress to a multiple organ dysfunction syndrome. In fact, all human structures that express ACE2 are susceptible to SARS-CoV-2 infection and/or to the downstream effects of reduced ACE2 levels, namely systemic inflammation and injury. In this review, we aim to summarize the major features of SARS-CoV-2 biology and the current understanding of COVID-19 pathogenesis, as well as its clinical repercussions in the lung, heart, kidney, bowel, liver, and brain. We also highlight potential therapeutic targets and current global efforts to identify safe and effective therapies against this life-threatening condition.

Mortality Benefit of Remdesivir in COVID-19: A Systematic Review and Meta-Analysis

Importance/Background: During current public health emergency of COVID-19 pandemic, repurposing of existing antiviral drugs may be an efficient strategy since there is no proven effective treatment. Published literature shows Remdesivir has broad-spectrum antiviral activity against numerous RNA viruses and has been recently recognized as a promising therapy against SARS-CoV-2.

Methods: A systematic search was conducted for full length manuscripts published between inception and July 19th, 2020 focussing on efficacy and safety of Remdesivir in COVID-19. The primary outcomes were defined as mortality rate and median days to recovery based on the available pooled data. The secondary outcome was adverse events rate and drug discontinuation rate.

Statistical Analysis: All outcomes were performed using Comprehensive Meta-Analysis software package (Bio stat, Englewood, NJ, USA).

Results: A total of 1,895 patients from 9 studies were included in this qualitative synthesis. In patients treated with Remdesivir, the mean recovery time was 15.84 days (95% CI 11.68–20, SE 2.12; I² = 97.24) and the pooled mortality rate was 11.3% (95% CI 7.9–16%; I² = 74.85). However, treatment with Remdesivir was associated with adverse effects (55.3%, 95% CI 31.5–76.9%; I² = 97.66) eventually warranting the discontinuation of the drug (17.8%, 95% CI 8.6–33.1%; I² = 95.64). The meta-analysis of three clinical trials indicated that administration of Remdesivir significantly reduces the mortality compared to the placebo (OR 0.70, 95% CI 0.58–0.84, p ≤ 0.001; I² = 16.6).

Conclusions and Relevance: The result of contemporary meta-analysis suggests mortality benefit with Remdesivir in COVID-19 and median recovery time was over 2 weeks. The pooled mortality with Remdesivir was found to be very low, and this analysis can shed light on this potential treatment for COVID-19 patients.

Correlation between SARS-COV-2 antibody screening by immunoassay and neutralizing antibody testing

Background

The efficacy of convalescent plasma (CP), an alternative for the treatment of COVID‐19, depends on high titers of neutralizing antibodies (nAbs), but assays for quantifying nAbs are not widely available. Our goal was to develop a strategy to predict high titers of nAbs based on the results of anti‐SARS‐CoV‐2 immunoassays and the clinical characteristics of CP donors.

Study Design and Methods

A total of 214 CP donors were enrolled and tested for the presence of anti‐SARS‐CoV‐2 antibodies (IgG) using two commercial immunoassays: EUROIMMUN (ELISA) and Abbott (Chemiluminescence). Quantification of nAbs was performed using the Cytopathic Effect‐based Virus Neutralization test. Three criteria for identifying donors with nAbs ≥ 1:160 were tested: – C1: Curve ROC; − C2: Conditional decision tree considering only the IA results and – C3: Conditional decision tree including both the IA results and the clinical variables.

Results

The performance of the immunoassays was similar referring to both S/CO and predictive value for identifying nAbs titers ≥1:160. Regarding the studied criteria for identifying CP donors with high nAbs titers: (a) C1 showed 76.1% accuracy if S/CO = 4.65, (b) C2 presented 76.1% accuracy if S/CO ≥4.57 and (c) C3 had 71.6% accuracy if S/CO was ≥4.57 or if S/CO was between 2.68‐4.57 and the last COVID‐19‐related symptoms were recent (within 19 days).

Conclusion

SARS‐CoV‐2 IgG immunoassays (S/CO) can be used to predict high anti‐SARS‐CoV‐2 nAbs titers. This study has proposed different criteria for identifying donors with ≥1:160 nAbs titers, all with high efficacy.

SARS-CoV-2: Outline, Prevention, and Decontamination

The new coronavirus began to spread around the world in late 2019. Initially, it was found only in China, but in the following days there were reported cases of infections in other countries. Subsequently, based on taxonomy, phylogeny, and accepted practice, the virus was officially designated as severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). As a result of the rapid spread of SARS-CoV-2 in different countries around the world, on March 11, 2020, the World Health Organization (WHO) announced a status change in the disease caused by this coronavirus-from an epidemic to a pandemic disease. Although the world is taking unprecedented efforts to control the spread of SARS-CoV-2, the number of confirmed cases is rising. Therefore, effective preventive measures are needed in order to limit the spread of illness. The prevention measures are mainly based on information on the virus transmission routes, its environmental stability, and persistence on commonly touched surfaces. Social distancing, mask usage, and good hygiene practice are the most important recommendations for general public. Healthcare professionals who are directly involved in SARS-CoV-2 patients care are more exposed to virus infection and additional protection measures are necessary, including protective suits, aprons, face shields, goggles, and gloves. Due to the stability of SARS-CoV-2 on different surfaces, such as glass, paper, or wood, proper disinfection is crucial. Several studies have shown that despite the virus's stability, it is sensitive to various disinfectants, such as ethanol, isopropanol, sodium hypochlorite, or hydrogen peroxide. These findings underline the importance of having comprehensive knowledge about SARS-CoV-2 and multidirectional strategies in order to limit the spread of the virus. This review is a summary of the most important information about SARS-CoV-2, such as its stability on different surfaces, protection strategies, and decontamination options.

Immunological perspectives on the pathogenesis, diagnosis, prevention and treatment of COVID-19

Coronavirus disease 2019 (COVID-19) is an acute respiratory disease caused by severe acute respiratory syndrome coronavirus 2 (SARS-COV-2). COVID-19 can spread to the entire body and cause multiple organ failure. It is a daunting challenge to control the fast growing worldwide pandemic because effective prevention and treatment strategies are unavailable currently. Generally, the immune response of the human body triggered by viral infection is essential for the elimination of the virus. However, severe COVID-19 patients may manifest dysregulated immune responses, such as lymphopenia, lymphocyte exhaustion, exacerbated antibody response, cytokine release syndrome (CRS), etc. Understanding of these immunological characteristics may help identify better approaches for diagnosis, prognosis and treatment of COVID-19 patients. As specific anti-viral agents are notoriously difficult to develop, strategies for modulating the immune responses by either developing novel vaccines or using immunotherapy hold great promise to improve the management of SARS-CoV-2 infection.

Convalescent plasma-mediated resolution of COVID-19 in a patient with humoral immunodeficiency

Convalescent plasma (CP) is widely used to treat COVID-19, but without formal evidence of efficacy. Here, we report the beneficial effects of CP in a severely ill COVID-19 patient with prolonged pneumonia and advanced chronic lymphocytic leukemia (CLL), who was unable to generate an antiviral antibody response of her own. On day 33 after becoming symptomatic, the patient received CP containing high-titer (ID50 > 5,000) neutralizing antibodies (NAbs), defervesced, and improved clinically within 48 h and was discharged on day 37. Hence, when present in sufficient quantities, NAbs to SARS-CoV-2 have clinical benefit even if administered relatively late in the disease course. However, analysis of additional CP units revealed widely varying NAb titers, with many recipients exhibiting endogenous NAb responses far exceeding those of the administered units. To obtain the full therapeutic benefits of CP immunotherapy, it will thus be important to determine the neutralizing activity in both CP units and transfusion candidates.

No SARS-CoV-2 RNA detected in the convalescent plasma of COVID-19 patients with different disease severity

Introduction

Convalescent plasma transfusion (CPT), a potential therapy for coronavirus disease 2019 (COVID-19), requires strict quality control of the donor blood. Whether to confirm the disappearance of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) RNA (RNAemia) in convalescent donor blood or not is unclear. Reports recommending the proof of viral disappearance from the blood are controversial. Foreseeing CPT in treating COVID-19 patients in Japan, we investigated RNAemia in 100 convalescent donors with mild, moderate, and severe COVID-19.

Methods

Between April 30 and July 30, 2020, we measured RNAemia in the plasma samples of donors with resolved COVID-19. Data on patients’ demographics, comorbidities, pneumonia, treatment, and real-time polymerase chain reaction results for SARS-CoV-2 were collected. Date of onset of initial symptoms or date of positive testing (for asymptomatic patients) were self-reported by the patients. Disease severity was defined as: no, mild, moderate oxygen demand, or severe (requiring mechanical ventilation).

Results

Of 100 donors (58 males [58.0%]; median age, 47 [range 22–69] years) screened as of July 30, 2020, 77 (77.0%); 19 (19.0%); and 4 (4.0%) had mild, moderate, and severe disease, respectively. Median time between onset and testing was 68.5 (range, 21–167) days. SARS-CoV-2 RNA was not detected in any of the plasma samples.

Conclusion

RNAemia was not found in recovered COVID-19 patients at least 21, 27, and 57 days after the onset of mild, moderate, and severe symptoms. Our study may contribute to determining a suitable time for collecting convalescent plasma from COVID-19 patients and to future CPT use.

A therapeutic neutralizing antibody targeting receptor binding domain of SARS-CoV-2 spike protein

Vaccines and therapeutics are urgently needed for the pandemic caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Here, we screen human monoclonal antibodies (mAb) targeting the receptor binding domain (RBD) of the viral spike protein via antibody library constructed from peripheral blood mononuclear cells of a convalescent patient. The CT-P59 mAb potently neutralizes SARS-CoV-2 isolates including the D614G variant without antibody-dependent enhancement effect. Complex crystal structure of CT-P59 Fab/RBD shows that CT-P59 blocks interaction regions of RBD for angiotensin converting enzyme 2 (ACE2) receptor with an orientation that is notably different from previously reported RBD-targeting mAbs. Furthermore, therapeutic effects of CT-P59 are evaluated in three animal models (ferret, hamster, and rhesus monkey), demonstrating a substantial reduction in viral titer along with alleviation of clinical symptoms. Therefore, CT-P59 may be a promising therapeutic candidate for COVID-19.

Therapies and vaccines for COVID-19, caused by the SARS-CoV-2 viral pandemic, are urgently needed. Here the authors establish and screen an antibody library from a convalescent COVID-19 patient to isolate a neutralizing antibody with the ability to reduce viral titer and alleviate symptoms in ferret, hamster, and rhesus monkey infection models.

COVID-19 pathogenesis, prognostic factors, and treatment strategy: Urgent recommendations

The pandemic of novel coronavirus disease (COVID-19) is not yet close to being over, more than 8 months after the first cases, but researchers are making great progress in fighting the disease. We have conducted a brief review of the geographic differences in the prevalence of COVID-19, the updated pathological findings, prognostic factors, and treatments for disease prevention and improvement of prognosis. Although hydroxychloroquine and tocilizumab have been recommended by some researchers, many clinical trials have failed to confirm any beneficial effect of these and other drugs on COVID-19, in terms of improved clinical status or reduced patient mortality. Currently, glucocorticoid is the only drug that reduces the mortality of COVID-19 in a randomized controlled trial; however, it is still necessary to establish the optimal timing of administration. It is also urgent to set up an international or national cohort to address the risk factors associated with infection, the natural history of COVID-19, including the disease type, surrogate markers for critically ill, long-term sequelae, and reinfection after exposure, identify responders to glucocorticoid, and establish optimal treatment strategies for disease control.

IgA and FcαRI: Versatile Players in Homeostasis, Infection, and Autoimmunity

Mucosal surfaces constitute the frontiers of the body and are the biggest barriers of our body for the outside world. Immunoglobulin A (IgA) is the most abundant antibody class present at these sites. It passively contributes to mucosal homeostasis via immune exclusion maintaining a tight balance between tolerating commensals and providing protection against pathogens. Once pathogens have succeeded in invading the epithelial barriers, IgA has an active role in host-pathogen defense by activating myeloid cells through divers receptors, including its Fc receptor, FcαRI (CD89). To evade elimination, several pathogens secrete proteins that interfere with either IgA neutralization or FcαRI-mediated immune responses, emphasizing the importance of IgA-FcαRI interactions in preventing infection. Depending on the IgA form, either anti- or pro-inflammatory responses can be induced. Moreover, the presence of excessive IgA immune complexes can result in continuous FcαRI-mediated activation of myeloid cells, potentially leading to severe tissue damage. On the one hand, enhancing pathogen-specific mucosal and systemic IgA by vaccination may increase protective immunity against infectious diseases. On the other hand, interfering with the IgA-FcαRI axis by monovalent targeting or blocking FcαRI may resolve IgA-induced inflammation and tissue damage. This review describes the multifaceted role of FcαRI as immune regulator between anti- and pro-inflammatory responses of IgA, and addresses potential novel therapeutic strategies that target FcαRI in disease.

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SARS-CoV-2 infection associated with hepatitis in an infant with X-linked severe combined immunodeficiency

X-linked severe combined immunodeficiency (X-SCID) is a disorder of adaptive immunity caused by mutations in the IL-2 receptor common gamma chain gene resulting in deficiencies of T and natural killer cells, coupled with severe dysfunction in B cells. X-SCID is lethal without allogeneic stem cell transplant or gene therapy due to opportunistic infections. An infant with X-SCID became infected with SARS-CoV-2 while awaiting transplant. The patient developed severe hepatitis without the respiratory symptoms typical of COVID-19. He was treated with convalescent plasma, and thereafter was confirmed to have SARS-CoV-2 specific antibodies, as detected with a microfluidic antigen array. After resolution of the hepatitis, he received a haploidentical CD34 selected stem cell transplant, without conditioning, from his father who had recovered from COVID-19. SARS CoV-2 was detected via RT-PCR on nasopharyngeal swabs until 61 days post transplantation. He successfully engrafted donor T and NK cells, and continues to do well clinically.

IgG Seroconversion and Pathophysiology in Severe Acute Respiratory Syndrome Coronavirus 2 Infection

We investigated the dynamics of seroconversion in severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection. During March 29-May 22, 2020, we collected serum samples and associated clinical data from 177 persons in London, UK, who had SARS-CoV-2 infection. We measured IgG against SARS-CoV-2 and compared antibody levels with patient outcomes, demographic information, and laboratory characteristics. We found that 2.0%-8.5% of persons did not seroconvert 3-6 weeks after infection. Persons who seroconverted were older, were more likely to have concurrent conditions, and had higher levels of inflammatory markers. Non-White persons had higher antibody concentrations than those who identified as White; these concentrations did not decline during follow-up. Serologic assay results correlated with disease outcome, race, and other risk factors for severe SARS-CoV-2 infection. Serologic assays can be used in surveillance to clarify the duration and protective nature of humoral responses to SARS-CoV-2 infection.

The art of the possible in approaching efficacy trials for COVID19 convalescent plasma

COVID-19 convalescent plasma (CCP) is widely used as a treatment. While safety data are enough, high-level evidences of efficacy are still missing. We summarize here the results from randomized controlled trials (RCT) published to date and analyze their flaws and biases. We then provide suggestions for next round of CCP RCTs, discussing specification of CCP, therapeutic dose, timing, control arm, disease stage, and outcome measures.

Severe COVID-19: A distinct entity

Severe coronavirus disease-2019 (COVID-19) is a distinct entity that rapidly evolves and may abruptly culminate in to a critical illness. As per Chinese experience, approximately, 15% of patients of COVID-19 progress to severe disease and 5% become critically ill. The incidence of severe and critical illness is higher among men, patients older than 65 years of age and in persons with other medical comorbidities. Cytokine storm cause pronounced lung damage and multiorgan failure. Coagulopathy is a key component of severe COVID-19. Critically ill patients are generally predisposed to a high risk of thromboembolism as well. Lymphopenia predisposes to severe disease. None of the antiviral or immunomodulators has proven efficacy in severe COVID-19. Supplemental oxygen need be administered in patients with hypoxemia. Excessive breathing effort, acute respiratory distress syndrome (ARDS), encephalopathy, and multiorgan failure are indications for mechanical ventilation. In a large number of patients, the overall outcome is poor. Health care workers in intensive care units are exposed to the enormous risk of acquiring hospital acquired SARS-COV-2 infection.

COVID-19 Convalescent Plasma: from donation to treatment - A Systematic Review & Single Center Experience

Convalescent plasma is an old treatment for a new disease. The coronavirus disease 2019 (COVID-19) pandemic caused the analysis of convalescent plasma to reemerge as a possible treatment. First, a systematic review summarizes the available research examining the use of convalescent plasma for the treatment of patients with COVID-19. Second, we describe our experience in establishing a single-center convalescent plasma donation program.

Clinical use of Convalescent Plasma in the COVID-19 pandemic: a transfusion-focussed gap analysis with recommendations for future research priorities

BACKGROUND AND OBJECTIVES

Use of convalescent plasma for coronavirus disease 2019 (COVID-19) treatment has gained interest worldwide. However, there is lack of evidence on its dosing, safety and effectiveness. Until data from clinical studies are available to provide solid evidence for worldwide applicable guidelines, there is a need to provide guidance to the transfusion community and researchers on this emergent therapeutic option. This paper aims to identify existing key gaps in current knowledge in the clinical application of COVID-19 convalescent plasma (CCP).

MATERIALS AND METHODS

The International Society of Blood Transfusion (ISBT) initiated a multidisciplinary working group with worldwide representation from all six continents with the aim of reviewing existing practices on CCP use from donor, product and patient perspectives. A subgroup of clinical transfusion professionals was formed to draft a document for CCP clinical application to identify the gaps in knowledge in existing literature.

RESULTS

Gaps in knowledge were identified in the following main domains: study design, patient eligibility, CCP dose, frequency and timing of CCP administration, parameters to assess response to CCP treatment and long-term outcome, adverse events and CCP application in less-resourced countries as well as in paediatrics and neonates.

CONCLUSION

This paper outlines a framework of gaps in the knowledge of clinical deployment of CPP that were identified as being most relevant. Studies to address the identified gaps are required to provide better evidence on the effectiveness and safety of CCP use.

Significantly Decreased Mortality in a Large Cohort of Coronavirus Disease 2019 (COVID-19) Patients Transfused Early with Convalescent Plasma Containing High-Titer Anti-Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) Spike Protein IgG

Coronavirus disease 2019 (COVID-19) convalescent plasma has emerged as a promising therapy and has been granted Emergency Use Authorization by the US Food and Drug Administration for hospitalized COVID-19 patients. We recently reported results from interim analysis of a propensity score-matched study suggesting that early treatment of COVID-19 patients with convalescent plasma containing high-titer anti-spike protein receptor binding domain (RBD) IgG significantly decreases mortality. We herein present results from a 60-day follow-up of a cohort of 351 transfused hospitalized patients. Prospective determination of enzyme-linked immunosorbent assay anti-RBD IgG titer facilitated selection and transfusion of the highest titer units available. Retrospective analysis by the Ortho VITROS IgG assay revealed a median signal/cutoff ratio of 24.0 for transfused units, a value far exceeding the recent US Food and Drug Administration-required cutoff of 12.0 for designation of high-titer convalescent plasma. With respect to altering mortality, our analysis identified an optimal window of 44 hours after hospitalization for transfusing COVID-19 patients with high-titer convalescent plasma. In the aggregate, the analysis confirms and extends our previous preliminary finding that transfusion of COVID-19 patients soon after hospitalization with high-titer anti-spike protein RBD IgG present in convalescent plasma significantly reduces mortality.

Systematic Review on the Therapeutic Options for COVID-19: Clinical Evidence of Drug Efficacy and Implications

A novel coronavirus-2 (SARS-CoV-2) was first identified in Wuhan, China, and quickly spread globally. Several treatments have been proposed, many of which have proven ineffective. Consequently, there is a need to review the published evidence of drug clinical trials to guide future prescribing. A systematic review of published clinical trials and retrospective observational studies was carried out. The search was made using PubMed, Embase, MEDLINE, and China National Knowledge Infrastructure (CNKI) databases. Articles published between January 2020 and October 2020 and written in the English language were retrieved and included in the study. Researches that used traditional medicine, in-vitro and in-vivo animal studies, as well as reviews were excluded. Seventy-three relevant articles that fulfilled the inclusion criteria were finally selected and reviewed. Hydroxychloroquine, chloroquine, and azithromycin produced no clinical evidence of efficacy in randomized controlled clinical trials (RCT). However, retrospective observational studies reported the efficacy of remdesivir and lopinavir/ritonavir in reducing viral load, although there have been concerns with lopinavir/ritonavir and, more recently, remdesivir. Recently, tocilizumab, dexamethasone, and methylprednisolone significantly relieved lung inflammation and decreased mortality in patients with severe COVID-19. In addition, convalescent plasma was effective in boosting strong immunity among patients with mild COVID-19. There is currently no single worldwide approved therapeutic option for patients with COVID-19 despite the initial hype with medicines, including hydroxychloroquine. Nonetheless, dexamethasone has shown promise in symptomatic treatment and convalescent plasma in boosting immunity. New treatments are currently being researched, and the findings will be reported accordingly to provide evidence-based guidance for prescribers and policymakers.

Pragmatic Recommendations for Therapeutics of Hospitalized COVID-19 Patients in Low- and Middle-Income Countries

The therapeutic options for COVID-19 patients are currently limited, but numerous randomized controlled trials are being completed, and many are on the way. For COVID-19 patients in low- and middle-income countries (LMICs), we recommend against using remdesivir outside of a clinical trial. We recommend against using hydroxychloroquine ± azithromycin or lopinavir-ritonavir. We suggest empiric antimicrobial treatment for likely coinfecting pathogens if an alternative infectious cause is likely. We suggest close monitoring without additional empiric antimicrobials if there are no clinical or laboratory signs of other infections. We recommend using oral or intravenous low-dose dexamethasone in adults with COVID-19 disease who require oxygen or mechanical ventilation. We recommend against using dexamethasone in patients with COVID-19 who do not require supplemental oxygen. We recommend using alternate equivalent doses of steroids in the event that dexamethasone is unavailable. We also recommend using low-dose corticosteroids in patients with refractory shock requiring vasopressor support. We recommend against the use of convalescent plasma and interleukin-6 inhibitors, such as tocilizumab, for the treatment of COVID-19 in LMICs outside of clinical trials.

Different aspects of convalescent plasma therapy for COVID-19 treatment; a critical review

The novel coronavirus disease (COVID-19) has been declared a pandemic by the World Health Organization (WHO) and is ominously threatening the survival of humankind on the whole planet. With a quick spread of the outbreak from its origin, Wuhan, China, to almost all over the world, it has affected more than seven million people to date, hence it has devastated every part of the infrastructural skeleton of governance. Continuously escalating disease burden and lack of proven therapeutic approaches are mounting challenges to health scientists and ultimately to healthcare providers. Although recent studies have shown benefits in decreasing the severity and duration of the illness and there are more benefits compared to risks, plasma therapy cannot be considered as a standard of care until the ongoing trials are completed and they establish definite evidence on its therapeutic efficacy and safety. Though a beneficial aspect may be there, acquiring donors and adequate availability of plasma is equally challenging, and its associated untoward effects related to biological therapeutic agents. The rational practice of CP therapy guided by risk-benefit judgment from aspects of donor and recipient can be a therapeutic option in such a global health crisis.

Convalescent Plasma Transfusion for the Treatment of COVID-19-Experience from Poland: A Multicenter Study

Because the optimal treatment for COVID-19 is still unknown, it is important to explore every potential way of improving the chances of survival for COVID-19 patients. The aim of the study was to analyze the effectiveness of convalescent plasma on COVID-19 patients. The study population consisted of 78 patients diagnosed with COVID-19, selected from the SARSTer national database, who received convalescent plasma. The impact on clinical and laboratory parameters was assessed. A clinical improvement was observed in 62 (79%) patients, and 10 (13%) patients died from COVID-19. No side effects of the convalescent plasma treatment were observed. When plasma was administered earlier than 7 days from diagnosis, the total hospitalization time was shorter (p < 0.05). Plasma efficacy was inferior to remdesivir in endpoints such as the necessity and duration of oxygen therapy, the duration of hospitalization, and mortality rate, and inferior to other drugs in the case of the duration of hospitalization and the necessity of constant oxygen therapy, but comparable in most other measured endpoints. A comparison of a 30-day mortality rate in patients who received plasma and remdesivir (4/25, 16%) and who received only plasma (6/53, 11%) showed no significant difference. Convalescent plasma efficacy is inferior to remdesivir when treating COVID-19 patients but the addition of remdesivir to plasma does not improve the treatment effectiveness. In most endpoints, plasma was comparable to other treatment options. In our opinion, convalescent plasma may be used as a supportive treatment in COVID-19 patients because of the low frequency of adverse effects and availability, but must be given as early from the diagnosis as possible.

Case Study: Prolonged Infectious SARS-CoV-2 Shedding from an Asymptomatic Immunocompromised Individual with Cancer

Long-term severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) shedding was observed from the upper respiratory tract of a female immunocompromised individual with chronic lymphocytic leukemia and acquired hypogammaglobulinemia. Shedding of infectious SARS-CoV-2 was observed up to 70 days, and of genomic and subgenomic RNA up to 105 days, after initial diagnosis. The infection was not cleared after the first treatment with convalescent plasma, suggesting a limited effect on SARS-CoV-2 in the upper respiratory tract of this individual. Several weeks after a second convalescent plasma transfusion, SARS-CoV-2 RNA was no longer detected. We observed marked within-host genomic evolution of SARS-CoV-2 with continuous turnover of dominant viral variants. However, replication kinetics in Vero E6 cells and primary human alveolar epithelial tissues were not affected. Our data indicate that certain immunocompromised individuals may shed infectious virus longer than previously recognized. Detection of subgenomic RNA is recommended in persistently SARS-CoV-2-positive individuals as a proxy for shedding of infectious virus.

Prevalent, protective, and convergent IgG recognition of SARS-CoV-2 non-RBD spike epitopes in COVID-19 convalescent plasma

Although humoral immunity is essential for control of SARS-CoV-2, the molecular composition, binding epitopes and effector functions of the immunoglobulin G (IgG) antibodies that circulate in blood plasma following infection are unknown. Proteomic deconvolution of the circulating IgG repertoire (Ig-Seq ¹ ) to the spike ectodomain (S-ECD ² ) in four convalescent study subjects revealed that the plasma response is oligoclonal and directed predominantly (>80%) to S-ECD epitopes that lie outside the receptor binding domain (RBD). When comparing antibodies directed to either the RBD, the N-terminal domain (NTD) or the S2 subunit (S2) in one subject, just four IgG lineages (1 anti-S2, 2 anti-NTD and 1 anti-RBD) accounted for 93.5% of the repertoire. Although the anti-RBD and one of the anti-NTD antibodies were equally potently neutralizing in vitro , we nonetheless found that the anti-NTD antibody was sufficient for protection to lethal viral challenge, either alone or in combination as a cocktail where it dominated the effect of the other plasma antibodies. We identified in vivo protective plasma anti-NTD antibodies in 3/4 subjects analyzed and discovered a shared class of antibodies targeting the NTD that utilize unmutated or near-germline IGHV1-24, the most electronegative IGHV gene in the human genome. Structural analysis revealed that binding to NTD is dominated by interactions with the heavy chain, accounting for 89% of the entire interfacial area, with germline residues uniquely encoded by IGHV1-24 contributing 20% (149 Å ² ). Together with recent reports of germline IGHV1-24 antibodies isolated by B-cell cloning ^3,4 our data reveal a class of shared IgG antibodies that are readily observed in convalescent plasma and underscore the role of NTD-directed antibodies in protection against SARS-CoV-2 infection.

Confidentiality challenges surrounding plasma therapy during the COVID-19 pandemic: a case discussion in Iran

Maintaining confidentiality, both in national and international codes of ethics, is considered an important principle in healthcare and the medical profession for both patients and physicians. This case-report article focused on a real case. Based on the request of the Iranian Blood Transfusion Organization (IBTO) for plasma donation from recovered COVID-19 patients, we asked the names and personal information of those patients from hospitals affiliated with Iran University of Medical Sciences (IUMS) and arranged for the subjects to be referred to the Medical Ethics Department of IUMS for consultation during the COVID-19 pandemic. Various ethical and legal aspects of this case were discussed in a special meeting, and practical solutions were then provided considering the limits of confidentiality and conditions for ethical access to patients' information during a pandemic. Since plasma therapy is not a definitive cure for COVID-19 and considering the ethical and legal points presented in this article, it is not recommended to announce the names of patients in the early stages. Given the potential impacts of the procedure and the possibility of patients being cured, however, their consent should be obtained in different situations and, if necessary, providing information to patients or educating them should be considered.