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

Coagulation profile of human COVID-19 convalescent plasma

Convalescent plasma is used to treat COVID-19. There are theoretical concerns about the impact of pro-coagulant factors in convalescent plasma on the coagulation cascade particularly among patients with severe COVID-19. The aim of this study was to evaluate the coagulation profile of COVID-19 convalescent plasma. Clotting times and coagulation factor assays were compared between fresh frozen plasma, COVID-19 convalescent plasma, and pathogen-reduced COVID-19 convalescent plasma. Measurements included prothrombin time, activated partial thromboplastin time, thrombin time, fibrinogen, D-dimer, von Willebrand factor activity, von Willebrand factor antigen, coagulation factors II, V, VII-XII, protein S activity, protein C antigen, and alpha-2 plasmin inhibitor. Clotting times and coagulation factor assays were not different between COVID-19 convalescent plasma and fresh frozen plasma, except for protein C antigen. When compared to fresh frozen plasma and regular convalescent plasma, pathogen reduction treatment increased activated partial thromboplastin time and thrombin time, while reducing fibrinogen, coagulation factor II, V, VIII, IX, X, XI, XII, protein S activity, and alpha-2 plasmin inhibitor. The coagulation profiles of human COVID-19 convalescent plasma and standard fresh frozen plasma are not different. Pathogen reduced COVID-19 convalescent plasma is associated with reduction of coagulation factors and a slight prolongation of coagulation times, as anticipated. A key limitation of the study is that the COVID-19 disease course of the convalesced donors was not characterized.

Are convalescent plasma stocks collected during former COVID-19 waves still effective against current SARS-CoV-2 variants?

COVID-19 convalescent plasma (CCP) was among the few frontline therapies used to treat COVID-19. After large randomized controlled trials (RCTs) relying on late use in hospitalized patients and/or low antibody titres failed to meet their predefined primary endpoint, the infectious disease community reduced usage of CCP in favour of monoclonal antibodies. Consequently, there are CCP stocks at most transfusion centres worldwide, although scattered usage continues. Further, better designed RCTs are also being launched. The urgent question here is: should we use CCP units collected months before given the largely changed viral variant landscape? We review here in vitro evidence that discourages usage of such CCP units against Delta and other variants of concern. CCP collections should be continued in order to update the armamentarium of therapeutics against vaccine breakthrough infections or in unvaccinated patients and is especially relevant in next-generation RCTs.

Development and Validation of a Treatment Benefit Index to Identify Hospitalized Patients With COVID-19 Who May Benefit From Convalescent Plasma

Importance

Identifying which patients with COVID-19 are likely to benefit from COVID-19 convalescent plasma (CCP) treatment may have a large public health impact.

Objective

To develop an index for predicting the expected relative treatment benefit from CCP compared with treatment without CCP for patients hospitalized for COVID-19 using patients' baseline characteristics.

Design, Setting, and Participants

This prognostic study used data from the COMPILE study, ie, a meta-analysis of pooled individual patient data from 8 randomized clinical trials (RCTs) evaluating CCP vs control in adults hospitalized for COVID-19 who were not receiving mechanical ventilation at randomization. A combination of baseline characteristics, termed the treatment benefit index (TBI), was developed based on 2287 patients in COMPILE using a proportional odds model, with baseline characteristics selected via cross-validation. The TBI was externally validated on 4 external data sets: the Expanded Access Program (1896 participants), a study conducted under Emergency Use Authorization (210 participants), and 2 RCTs (with 80 and 309 participants).

Exposure

Receipt of CCP.

Main Outcomes and Measures

World Health Organization (WHO) 11-point ordinal COVID-19 clinical status scale and 2 derivatives of it (ie, WHO score of 7-10, indicating mechanical ventilation to death, and WHO score of 10, indicating death) at day 14 and day 28 after randomization. Day 14 WHO 11-point ordinal scale was used as the primary outcome to develop the TBI.

Results

A total of 2287 patients were included in the derivation cohort, with a mean (SD) age of 60.3 (15.2) years and 815 (35.6%) women. The TBI provided a continuous gradation of benefit, and, for clinical utility, it was operationalized into groups of expected large clinical benefit (B1; 629 participants in the derivation cohort [27.5%]), moderate benefit (B2; 953 [41.7%]), and potential harm or no benefit (B3; 705 [30.8%]). Patients with preexisting conditions (diabetes, cardiovascular and pulmonary diseases), with blood type A or AB, and at an early COVID-19 stage (low baseline WHO scores) were expected to benefit most, while those without preexisting conditions and at more advanced stages of COVID-19 could potentially be harmed. In the derivation cohort, odds ratios for worse outcome, where smaller odds ratios indicate larger benefit from CCP, were 0.69 (95% credible interval [CrI], 0.48-1.06) for B1, 0.82 (95% CrI, 0.61-1.11) for B2, and 1.58 (95% CrI, 1.14-2.17) for B3. Testing on 4 external datasets supported the validation of the derived TBIs.

Conclusions and Relevance

The findings of this study suggest that the CCP TBI is a simple tool that can quantify the relative benefit from CCP treatment for an individual patient hospitalized with COVID-19 that can be used to guide treatment recommendations. The TBI precision medicine approach could be especially helpful in a pandemic.

Association of Convalescent Plasma Treatment With Clinical Status in Patients Hospitalized With COVID-19: A Meta-analysis

Importance

COVID-19 convalescent plasma (CCP) is a potentially beneficial treatment for COVID-19 that requires rigorous testing.

Objective

To compile individual patient data from randomized clinical trials of CCP and to monitor the data until completion or until accumulated evidence enables reliable conclusions regarding the clinical outcomes associated with CCP.

Data Sources

From May to August 2020, a systematic search was performed for trials of CCP in the literature, clinical trial registry sites, and medRxiv. Domain experts at local, national, and international organizations were consulted regularly.

Study Selection

Eligible trials enrolled hospitalized patients with confirmed COVID-19, not receiving mechanical ventilation, and randomized them to CCP or control. The administered CCP was required to have measurable antibodies assessed locally.

Data Extraction and Synthesis

A minimal data set was submitted regularly via a secure portal, analyzed using a prespecified bayesian statistical plan, and reviewed frequently by a collective data and safety monitoring board.

Main Outcomes and Measures

Prespecified coprimary end points-the World Health Organization (WHO) 11-point ordinal scale analyzed using a proportional odds model and a binary indicator of WHO score of 7 or higher capturing the most severe outcomes including mechanical ventilation through death and analyzed using a logistic model-were assessed clinically at 14 days after randomization.

Results

Eight international trials collectively enrolled 2369 participants (1138 randomized to control and 1231 randomized to CCP). A total of 2341 participants (median [IQR] age, 60 [50-72] years; 845 women [35.7%]) had primary outcome data as of April 2021. The median (IQR) of the ordinal WHO scale was 3 (3-6); the cumulative OR was 0.94 (95% credible interval [CrI], 0.74-1.19; posterior probability of OR <1 of 71%). A total of 352 patients (15%) had WHO score greater than or equal to 7; the OR was 0.94 (95% CrI, 0.69-1.30; posterior probability of OR <1 of 65%). Adjusted for baseline covariates, the ORs for mortality were 0.88 at day 14 (95% CrI, 0.61-1.26; posterior probability of OR <1 of 77%) and 0.85 at day 28 (95% CrI, 0.62-1.18; posterior probability of OR <1 of 84%). Heterogeneity of treatment effect sizes was observed across an array of baseline characteristics.

Conclusions and Relevance

This meta-analysis found no association of CCP with better clinical outcomes for the typical patient. These findings suggest that real-time individual patient data pooling and meta-analysis during a pandemic are feasible, offering a model for future research and providing a rich data resource.

SARS-CoV-2 Neutralization in Convalescent Plasma and Commercial Lots of Plasma-Derived Immunoglobulin

INTRODUCTION

Patients with primary or secondary immunodeficiency (PID or SID) face increased insecurity and discomfort in the light of the COVID-19 pandemic, not knowing if and to what extent their comorbidities may impact the course of a potential SARS-CoV-2 infection. Furthermore, recently available vaccination options might not be amenable or effective for all patients in this heterogeneous population. Therefore, these patients often rely on passive immunization with plasma-derived, intravenous or subcutaneous immunoglobulin (IVIG/SCIG). Whether the ongoing COVID-19 pandemic and/or the progress in vaccination programs lead to increased and potentially protective titers in plasma-derived immunoglobulins (Ig) indicated (e.g., for humoral immunodeficiency) remains a pressing question for this patient population.

PURPOSE

We investigated SARS-CoV-2 reactivity of US plasma-derived IVIG/SCIG products from the end of 2020 until June 2021 as well as in convalescent plasma (CP) from May 2020 to August 2020 to determine whether potentially neutralizing antibody titers may be present.

METHODS

Final containers of IVIG/SCIG and CP donations were analyzed by commercial ELISA for anti-SARS-CoV-2 S1-receptor binding domain (RBD) IgG as well as microneutralization assay using a patient-derived SARS-CoV-2 (D614G) isolate. Neutralization capacities of 313 single plasma donations and 119 plasma-derived IVIG/SCIG lots were determined. Results obtained from both analytical methods were normalized against the WHO International Standard. Finally, based on dense pharmacokinetic profiles of an IVIG preparation from previously published investigations, possible steady-state plasma levels of SARS-CoV-2 neutralization capacities were approximated based on currently measured anti-SARS-CoV-2 potencies in IVIG/SCIG preparations.

RESULTS

CP donations presented with high variability with regards to anti-SARS-CoV-2 reactivity in ELISA as well as in neutralization testing. While approximately 50% of convalescent donations were not/low neutralizing, approximately 10% were at or above 600 IU/mL. IVIG/SCIG lots derived from pre-pandemic plasma donations did not show neutralizing capacities for SARS-CoV-2. Lots produced between December 2020 and June 2021 entailing plasma donations after the emergence of SARS-CoV-2 showed a rapid and constant increase in anti-SARS-CoV-2 reactivity and neutralization capacity over time. While lot-to-lot variability was substantial, neutralization capacity increased from a mean of 21 IU/mL in December 2020 to 506 IU/mL in June 2021 with a maximum of 864 IU/mL for the most recent lots. Pharmacokinetic extrapolations, based on non-compartmental superposition principles using steady-state reference profiles from previously published pharmacokinetic investigations on IVIG in PID, yielded potential steady-state trough plasma levels of 16 IU/mL of neutralizing SARS-CoV-2 IgG based on the average final container concentration from May 2021 of 216 IU/mL. Maximum extrapolated trough levels could reach 64 IU/mL based on the latest maximal final container potency tested in June 2021.

CONCLUSIONS

SARS-CoV-2 reactivity and neutralization capacity in IVIG/SCIG produced from US plasma rapidly and in part exponentially increased in the first half of 2021. The observed increase of final container potencies is likely trailing the serological status of the US donor population in terms of COVID-19 convalescence and vaccination by at least 5 months due to production lead times and should in principle continue at least until Fall 2021. In summary, the data support rapidly increasing levels of anti-SARS-CoV-2 antibodies in IVIG/SCIG products, implicating that a certain level of protection could be possible against COVID-19 for regularly substituted PID/SID patients. Nevertheless, more research is still needed to confirm which plasma levels are needed to provide protection against SARS-CoV-2 infection in immune-compromised patients.

Convalescent plasma therapy against the emerging SARS-CoV-2 variants: Delineation of the potentialities and risks

Coronavirus disease 2019 (COVID-19) caused by severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) has resulted in a catastrophic pandemic and severely impacted people's livelihoods worldwide. In addition, the emergence of SARS-CoV-2 variants has posed a severe threat to humankind. Due to the dearth of therapeutic options during the commencement of the pandemic, convalescent plasma therapy (CPT) played a significant part in the management of patients with severe form of COVID-19. Several recent studies have proposed various protective effects of CPT, such as antiviral, anti-inflammatory, anti-thrombotic, and immunomodulatory actions, curtailing the devastating consequences of the SARS-CoV-2 infection. On the contrary, several clinical studies have raised some serious concerns about the effectiveness and reliability of CPT in the management of patients with COVID-19. The protective effects of CPT in severely ill patients are yet to be proved. Moreover, the emergence of SARS-CoV-2 variants has raised concerns about the effectiveness of CPT against COVID-19. Therefore, to establish concrete evidence of the efficacy of CPT and adjudicate its inclusion in the management of COVID-19, an updated review of present literature is required, which could help in the development of an efficient therapeutic regimen to treat COVID-19 amid the emergence of new viral variants.

Outcomes of SOT Recipients With COVID-19 in Different Eras of COVID-19 Therapeutics

BACKGROUND

Few reports have focused on newer coronavirus disease 2019 (COVID-19) therapies (remdesivir, dexamethasone, and convalescent plasma) in solid organ transplant recipients; concerns had been raised regarding possible adverse impact on allograft function or secondary infections.

METHODS

We studied 77 solid organ transplant inpatients with COVID-19 during 2 therapeutic eras (Era 1: March-May 2020, 21 patients; and Era 2: June-November 2020, 56 patients) and 52 solid organ transplant outpatients.

RESULTS

In Era 1, no patients received remdesivir or dexamethasone, and 4 of 21 (19.4%) received convalescent plasma, whereas in Era 2, remdesivir (24/56, 42.9%), dexamethasone (24/56, 42.9%), and convalescent plasma (40/56, 71.4%) were commonly used. Mortality was low across both eras, 4 of 77 (5.6%), and rejection occurred in only 2 of 77 (2.8%) inpatients; infections were similar in hypoxemic patients with or without dexamethasone. Preexisting graft dysfunction was associated with greater need for hospitalization, higher severity score, and lower survival. Acute kidney injury was present in 37.3% of inpatients; renal function improved more rapidly in patients who received remdesivir and convalescent plasma. Post-COVID-19 renal and liver function were comparable between eras, out to 90 d.

CONCLUSIONS

Newer COVID-19 therapies did not appear to have a deleterious effect on allograft function, and infectious complications were comparable.

OUP accepted manuscript

Passive antibody immunotherapeutics directed against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) are promising countermeasures for protection and treatment of coronavirus disease 2019 (COVID-19). SARS-CoV-2 variants of concern (VOCs) and variants of interest (VOIs) can impact the clinical efficacy of immunotherapeutics. A fully human polyclonal antibody immunotherapeutic purified from plasma of transchromosomic (Tc) bovines hyperimmunized with SARS-CoV-2 WA-1 spike (SAB-185) is being assessed for efficacy in a phase 2/3 clinical trial when different circulating SARS-CoV-2 variants predominated. We evaluated antibody binding, avidity maturation, and SARS-CoV-2 VOCs/VOIs virus-neutralizing capacity of convalescent plasma compared with different lots of SAB-185 and individual Tc bovine sera sequentially obtained after each vaccination against Alpha, Epsilon, Iota, Gamma, Beta, Kappa, and Delta variants. In contrast to convalescent plasma, sera and SAB-185 derived from hyperimmunized Tc bovines demonstrated higher antibody avidity and more potent cross-neutralizing activity of VOCs/VOIs. Thus, SAB-185 is a potential promising therapeutic candidate for the treatment of patients infected with SARS-CoV-2 variants.

Management of COVID patients with convalescent plasma: Do we have the final word?

Immunotherapy with convalescent plasma (CP) has been used in the past in several different infectious diseases and proposed as a potential therapeutic option in patients with COVID-19. However, a clear benefit was never demonstrated and randomized clinical trials (RCTs) conducted in different populations of COVID-19 patients showed contrasting results. In general, current evidences suggest that CP in patients with moderate to severe COVID-19 does not reduce the progression to severe respiratory failure or death within 30 days. However, currently published RCTs have several limitations. The administration of plasma with low titer of neutralizing antibodies (NAbs), the use of suboptimal surrogate serological tests to determine NAbs titer, the delayed administration of CP from the onset of COVID-19 symptoms and the lack of information about antibody titer of recipients before CP infusion, are all limiting factors that may have affected the study results. Thus, a potential benefit of early (within the first 72 h from onset of symptoms), high titer CP in patients with mild COVID-19 (pO2/FiO2>300) cannot be definitively excluded. However, immunotherapy with monoclonal antibodies developed from CP demonstrated efficacy in reducing progression to severe COVID-19 and hospitalization and are today recommended in the early phase of COVID-19.

Mechanisms of SARS-CoV-2 entry into cells

The unprecedented public health and economic impact of the COVID-19 pandemic caused by infection with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has been met with an equally unprecedented scientific response. Much of this response has focused, appropriately, on the mechanisms of SARS-CoV-2 entry into host cells, and in particular the binding of the spike (S) protein to its receptor, angiotensin-converting enzyme 2 (ACE2), and subsequent membrane fusion. This Review provides the structural and cellular foundations for understanding the multistep SARS-CoV-2 entry process, including S protein synthesis, S protein structure, conformational transitions necessary for association of the S protein with ACE2, engagement of the receptor-binding domain of the S protein with ACE2, proteolytic activation of the S protein, endocytosis and membrane fusion. We define the roles of furin-like proteases, transmembrane protease, serine 2 (TMPRSS2) and cathepsin L in these processes, and delineate the features of ACE2 orthologues in reservoir animal species and S protein adaptations that facilitate efficient human transmission. We also examine the utility of vaccines, antibodies and other potential therapeutics targeting SARS-CoV-2 entry mechanisms. Finally, we present key outstanding questions associated with this critical process.

Update on and Future Directions for Use of Anti-SARS-CoV-2 Antibodies: National Institutes of Health Summit on Treatment and Prevention of COVID-19

As the fourth wave of the SARS-CoV-2 pandemic encircles the globe, there remains an urgent challenge to identify safe and effective treatment and prevention strategies that can be implemented in a range of health care and clinical settings. Substantial advances have been made in the use of anti-SARS-CoV-2 antibodies to mitigate the morbidity and mortality associated with COVID-19. On 15 June 2021, the National Institutes of Health, in collaboration with the U.S. Food and Drug Administration, convened a virtual summit to summarize existing knowledge on anti-SARS-CoV-2 antibodies and to identify key unanswered scientific questions to further catalyze the clinical development and implementation of antibodies.

Effectiveness and Controversy of Convalescent Plasma Therapy for Coronavirus Disease 2019 Patients

Since the coronavirus disease 2019 (COVID-19) began to spread, it remains pandemic worldwide. The European Medicines Agency's human medicines committee and Food and Drug Administration have only granted a conditional marketing authorization for remdesivir to treat COVID-19. It is essential to apply other valuable treatments. Convalescent plasma (CP), donated by persons who have recovered from COVID-19, is the cellular component of blood that contains specific antibodies. Therefore, to determine the feasibility of CP for COVID-19, the effectiveness and controversy are discussed in depth here. It is suggested that CP plays a certain role in the treatment of COVID-19. As a treatment, it may have its own indications and contraindications, which need to be further discussed. Meanwhile, it is critical to establish a standard procedure for treatment from CP collection, preservation, transport, to transfusion, and conduct some large sample randomized controlled trials to confirm the transfusion dosage, appropriate time, frequency, and actively prevent adverse outcomes that may occur.

Convalescent Plasma for Patients Hospitalized With Coronavirus Disease 2019: A Meta-Analysis With Trial Sequential Analysis of Randomized Controlled Trials

Current evidence from randomized controlled trials (RCTs) and systematic reviews on the utility of convalescent plasma (CP) in patients with coronavirus disease 2019 (COVID-19) suggests a lack of benefit. We conducted an updated meta-analysis of RCTs with trial sequential analysis to investigate whether convalescent plasma is futile in reducing mortality in patients hospitalized with COVID-19. We searched 6 databases from December 1, 2019 to August 1, 2021 for RCTs comparing the use of CP with standard of care or transfusion of non-CP standard plasma in patients with COVID-19. The risk of bias was assessed using the Cochrane Risk-of-Bias 2 Tool. Random effects (DerSimonian and Laird) meta-analyses were conducted. The primary outcome was the aggregate risk for in-hospital mortality between both arms. We conducted a trial sequential analysis (TSA) based on the pooled relative risks (RRs) for in-hospital mortality. Secondary outcomes included the pooled RR for receipt of mechanical ventilation and mean difference in hospital length of stay. We included 18 RCTs (8702 CP, 7906 control). CP was not associated with a significant mortality benefit (RR: 0.95, 95%-CI: 0.86-1.04, P = .27, high certainty). Subgroup analysis did not find any significant differences (pinteraction = 0.30) between patients who received CP within 8 days of symptom onset (RR: 0.97, 95%-CI: 0.79-1.19, P = .80), or after 8 days (RR: 0.79, 95%-CI: 0.57-1.10, P = .16). TSA based on a RR reduction of 10% from a baseline mortality of 20% found that CP was not effective, with the pooled effect within the boundary for futility. CP did not significantly reduce the requirement for mechanical ventilation (RR: 1.00, 95%-CI: 0.91-1.10, P = .99, moderate certainty) or hospital length of stay (+1.32, 95%-CI: -1.86 to +4.52, P = .42, low certainty). CP does not improve relevant clinical outcomes in patients with COVID-19, especially in severe disease. The pooled effect of mortality was within the boundary of futility, suggesting the lack of benefit of CP in patients hospitalized with COVID-19.

Epidemiological Characteristics of Hospitalized Patients with Moderate versus Severe COVID-19 Infection: A Retrospective Cohort Single Centre Study

COVID-19 has a devastating impact worldwide. Recognizing factors that cause its progression is important for the utilization of appropriate resources and improving clinical outcomes. In this study, we aimed to identify the epidemiological and clinical characteristics of patients who were hospitalized with moderate versus severe COVID-19 illness. A single-center, retrospective cohort study was conducted between 3 March and 9 September 2020. Following the CDC guidelines, a two-category variable for COVID-19 severity (moderate versus severe) based on length of stay, need for intensive care or mechanical ventilation and mortality was developed. Data including demographic, clinical characteristics, laboratory parameters, therapeutic interventions and clinical outcomes were assessed using descriptive and inferential analysis. A total of 1002 patients were included, the majority were male (n = 646, 64.5%), Omani citizen (n = 770, 76.8%) and with an average age of 54.2 years. At the bivariate level, patients classified as severe were older (Mean = 55.2, SD = 16) than the moderate patients (Mean = 51.5, SD = 15.8). Diabetes mellitus was the only significant comorbidity potential factor that was more prevalent in severe patients than moderate (n = 321, 46.6%; versus n = 178, 42.4%; p < 0.001). Under the laboratory factors; total white cell count (WBC), C-reactive protein (CRP), Lactate dehydrogenase (LDH), D-dimer and corrected calcium were significant. All selected clinical characteristics and therapeutics were significant. At the multivariate level, under demographic factors, only nationality was significant and no significant comorbidity was identified. Three clinical factors were identified, including; sepsis, Acute respiratory disease syndrome (ARDS) and requirement of non-invasive ventilation (NIV). CRP and steroids were also identified under laboratory and therapeutic factors, respectively. Overall, our study identified only five factors from a total of eighteen proposed due to their significant values (p < 0.05) from the bivariate analysis. There are noticeable differences in levels of COVID-19 severity among nationalities. All the selected clinical and therapeutic factors were significant, implying that they should be a key priority when assessing severity in hospitalized COVID-19 patients. An elevated level of CRP may be a valuable early marker in predicting the progression in non-severe patients with COVID-19. Early recognition and intervention of these factors could ease the management of hospitalized COVID-19 patients and reduce case fatalities as well medical expenditure.

SARS-CoV-2 Infection of Rhesus Macaques Treated Early with Human COVID-19 Convalescent Plasma

Human clinical studies investigating use of convalescent plasma (CP) for treatment of coronavirus disease 2019 (COVID-19) have produced conflicting results. Outcomes in these studies may vary at least partly due to different timing of CP administration relative to symptom onset. The mechanisms of action of CP include neutralizing antibodies but may extend beyond virus neutralization to include normalization of blood clotting and dampening of inflammation. Unresolved questions include the minimum therapeutic titer in the CP units or CP recipient as well as the optimal timing of administration. Here, we show that treatment of macaques with CP within 24 h of infection does not reduce viral shedding in nasal or lung secretions compared to controls and does not detectably improve any clinical endpoint. We also demonstrate that CP administration does not impact viral sequence diversity in vivo, although the selection of a viral sequence variant in both macaques receiving normal human plasma was suggestive of immune pressure. Our results suggest that CP, administered to medium titers, has limited efficacy, even when given very early after infection. Our findings also contribute information important for the continued development of the nonhuman primate model of COVID-19. These results should inform interpretation of clinical studies of CP in addition to providing insights useful for developing other passive immunotherapies and vaccine strategies. IMPORTANCE Antiviral treatment options for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) remain very limited. One treatment that was explored beginning early in the pandemic (and that is likely to be tested early in future pandemics) is plasma collected from people who have recovered from coronavirus disease 2019 (COVID-19), known as convalescent plasma (CP). We tested if CP reduces viral shedding or disease in a nonhuman primate model. Our results demonstrate that administration of CP 1 day after SARS-CoV-2 infection had no significant impact on viral loads, clinical disease, or sequence diversity, although treatment with normal human plasma resulted in selection of a specific viral variant. Our results demonstrate that passive immunization with CP, even during early infection, provided no significant benefit in a nonhuman primate model of SARS-CoV-2 infection.

Identification and Development of Therapeutics for COVID-19

After emerging in China in late 2019, the novel coronavirus severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) spread worldwide, and as of mid-2021, it remains a significant threat globally. Only a few coronaviruses are known to infect humans, and only two cause infections similar in severity to SARS-CoV-2: Severe acute respiratory syndrome-related coronavirus, a species closely related to SARS-CoV-2 that emerged in 2002, and Middle East respiratory syndrome-related coronavirus, which emerged in 2012. Unlike the current pandemic, previous epidemics were controlled rapidly through public health measures, but the body of research investigating severe acute respiratory syndrome and Middle East respiratory syndrome has proven valuable for identifying approaches to treating and preventing novel coronavirus disease 2019 (COVID-19). Building on this research, the medical and scientific communities have responded rapidly to the COVID-19 crisis and identified many candidate therapeutics. The approaches used to identify candidates fall into four main categories: adaptation of clinical approaches to diseases with related pathologies, adaptation based on virological properties, adaptation based on host response, and data-driven identification (ID) of candidates based on physical properties or on pharmacological compendia. To date, a small number of therapeutics have already been authorized by regulatory agencies such as the Food and Drug Administration (FDA), while most remain under investigation. The scale of the COVID-19 crisis offers a rare opportunity to collect data on the effects of candidate therapeutics. This information provides insight not only into the management of coronavirus diseases but also into the relative success of different approaches to identifying candidate therapeutics against an emerging disease. IMPORTANCE The COVID-19 pandemic is a rapidly evolving crisis. With the worldwide scientific community shifting focus onto the SARS-CoV-2 virus and COVID-19, a large number of possible pharmaceutical approaches for treatment and prevention have been proposed. What was known about each of these potential interventions evolved rapidly throughout 2020 and 2021. This fast-paced area of research provides important insight into how the ongoing pandemic can be managed and also demonstrates the power of interdisciplinary collaboration to rapidly understand a virus and match its characteristics with existing or novel pharmaceuticals. As illustrated by the continued threat of viral epidemics during the current millennium, a rapid and strategic response to emerging viral threats can save lives. In this review, we explore how different modes of identifying candidate therapeutics have borne out during COVID-19.

SARS-CoV-2 Antiviral Therapy

The development of effective antiviral therapy for COVID-19 is critical for those awaiting vaccination, as well as for those who do not respond robustly to vaccination. This review summarizes 1 year of progress in the race to develop antiviral therapies for COVID-19, including research spanning preclinical and clinical drug development efforts, with an emphasis on antiviral compounds that are in clinical development or that are high priorities for clinical development. The review is divided into sections on compounds that inhibit SARS-CoV-2 enzymes, including its polymerase and proteases; compounds that inhibit virus entry, including monoclonal antibodies; interferons; and repurposed drugs that inhibit host processes required for SARS-CoV-2 replication. The review concludes with a summary of the lessons to be learned from SARS-CoV-2 drug development efforts and the challenges to continued progress.

A randomized controlled study of convalescent plasma for individuals hospitalized with COVID-19 pneumonia

BackgroundAntibody-based strategies for COVID-19 have shown promise in prevention and treatment of early disease. COVID-19 convalescent plasma (CCP) has been widely used but results from randomized trials supporting its benefit in hospitalized patients with pneumonia are limited. Here, we assess the efficacy of CCP in severely ill, hospitalized adults with COVID-19 pneumonia.MethodsWe performed a randomized control trial (PennCCP2), with 80 adults hospitalized with COVID-19 pneumonia, comparing up to 2 units of locally sourced CCP plus standard care versus standard care alone. The primary efficacy endpoint was comparison of a clinical severity score. Key secondary outcomes include 14- and 28-day mortality, 14- and 28-day maximum 8-point WHO ordinal score (WHO8) score, duration of supplemental oxygenation or mechanical ventilation, respiratory SARS-CoV-2 RNA, and anti-SARS-CoV-2 antibodies.ResultsEighty hospitalized adults with confirmed COVID-19 pneumonia were enrolled at median day 6 of symptoms and day 1 of hospitalization; 60% were anti-SARS-CoV-2 antibody seronegative. Participants had a median of 3 comorbidities, including risk factors for severe COVID-19 and immunosuppression. CCP treatment was safe and conferred significant benefit by clinical severity score (median [MED] and interquartile range [IQR] 10 [5.5-30] vs. 7 [2.75-12.25], P = 0.037) and 28-day mortality (n = 10, 26% vs. n = 2, 5%; P = 0.013). All other prespecified outcome measures showed weak evidence toward benefit of CCP.ConclusionTwo units of locally sourced CCP administered early in hospitalization to majority seronegative participants conferred a significant benefit in clinical severity score and 28-day mortality. Results suggest CCP may benefit select populations, especially those with comorbidities who are treated early.Trial RegistrationClinicalTrials.gov NCT04397757.FundingUniversity of Pennsylvania.

COVID-19 convalescent plasma: Evolving strategies for serological screening in France

Quantitation of anti-SARS-CoV-2 (severe acute respiratory syndrome coronavirus 2) neutralizing antibodies (Nabs) is a key parameter in determining the effective dose for treatment with COVID-19 convalescent plasma (CCP). Interpretation of results from clinical trials conducted worldwide requires comparison of Nabs titres obtained from different methods. As virus neutralization tests (VNTs) are not standardized scalable or commercially available, strategies based on intensity of ELISA (Enzyme Linked Immunosorbent Assay) or chemiluminescent binding serological tests were implemented to allow comparisons and establish criteria for determining 'high-titres' of anti-SARS-CoV-2 antibodies (Abs). To this end, the FDA (Food and Drug Administration) has proposed criteria to define high-titre plasmas using different serological assays, including the one used in France for the CCP SARS-CoV-2 Abs screening (Euroimmun anti-S1 IgG). A retrospective study revealed that when using the FDA criteria (ELISA signal-to-cut-off [S/C ratio] ≥3.5), 91% of CCP had Nabs titres ≥40 as assessed with an in-house VNT. French strategy to ensure sufficient stocks of CCP of increasing titre has evolved over time. Recently, we improved our strategy by collecting only plasma from vaccinated convalescent donors as we confirmed that the mean IgG antibody level (ELISA S/C ratio) was significantly higher in plasma from vaccinated convalescent donors compared to donations from unvaccinated convalescent donors: 9.31 (CI 95%: 8.46-10.16) versus 3.22 (CI 95%: 3.05-3.39) (p < 0.001).

Therapeutic Options for Coronavirus Disease 2019 (COVID-19): Where Are We Now?

PURPOSE OF REVIEW

Rapidly evolving treatment paradigms of coronavirus disease 2019 (COVID-19) introduce challenges for clinicians to keep up with the pace of published literature and to critically appraise the voluminous data produced. This review summarizes the clinical evidence from key studies examining the place of therapy of recommended drugs and management strategies for COVID-19.

RECENT FINDINGS

The global magnitude and duration of the pandemic have resulted in a flurry of interventional treatment trials evaluating both novel and repurposed drugs targeting various aspects of the viral life cycle. Additionally, clinical observations have documented various stages or phases of COVID-19 and underscored the importance of timing for the efficacy of studied therapies. Since the start of the COVID-19 pandemic, many observational, retrospective, and randomized controlled studies have been conducted to guide management of COVID-19 using drug therapies and other management strategies. Large, randomized, or adaptive platform trials have proven the most informative to guide recommended treatments to-date. Antimicrobial stewardship programs can play a pivotal role in ensuring appropriate use of COVID-19 therapies based on evolving clinical data and limiting unnecessary antibiotics given low rates of co-infection.

SUMMARY

Given the rapidly evolving medical literature and treatment paradigms, it is recommended to reference continuously updated, curated guidelines from national and international sources. While the drugs and management strategies mentioned in this review represent the current state of recommendations, many therapies are still under investigation to further define optimal COVID-19 treatment.

SUPPLEMENTARY INFORMATION

The online version contains supplementary material available at 10.1007/s11908-021-00769-8.

Sex-related susceptibility in coronavirus disease 2019 (COVID-19): Proposed mechanisms

The importance of sex differences is increasingly acknowledged in the incidence and treatment of disease. Accumulating clinical evidence demonstrates that sex differences are noticeable in COVID-19, and the prevalence, severity, and mortality rate of COVID-19 are higher among males than females. Sex-related genetic and hormonal factors and immunological responses may underlie the sex bias in COVID-19 patients. Angiotensin-converting enzyme 2 (ACE2) and transmembrane protease/serine subfamily member 2 (TMPRSS2) are essential proteins involved in the cell entry of SARS-CoV-2. Since ACE2 is encoded on the X-chromosome, a double copy of ACE2 in females may compensate for virus-mediated downregulation of ACE2, and thus ACE2-mediated cellular protection is greater in females. The X chromosome also contains the largest immune-related genes leading females to develop more robust immune responses than males. Toll-like receptor-7 (TLR-7), one of the key players in innate immunity, is linked to sex differences in autoimmunity and vaccine efficacy, and its expression is greater in females. Sex steroids also affect immune cell function. Estrogen contributes to higher CD4⁺ and CD8⁺ T cell activation levels, and females have more B cells than males. Sex differences not only affect the severity and progression of the disease, but also alter the efficacy of pharmacological treatment and adverse events related to the drugs/vaccines used against COVID-19. Administration of different drugs/vaccines in different doses or intervals may be useful to eliminate sex differences in efficacy and side/adverse effects. It should be noted that studies should include sex-specific analyses to develop further sex-specific treatments for COVID-19.

COVID-19 in a patient with Good's syndrome and in 13 patients with common variable immunodeficiency

Antibody deficiencies constitute the majority of primary immunodeficiencies in adults. These patients have a well-established increased risk of bacterial infections but there is a lack of knowledge regarding the relative risks upon contracting COVID-19. In this monocentric study the disease course of COVID-19 in 1 patient with Good's syndrome and in 13 patients with common variable immunodeficiency (CVID) is described. The severity of disease ranged from very mild to severe. Several patients required hospitalization and immunomodulatory treatment but all survived. Although viral infections are not a typical feature of humoral immunodeficiencies we recommend that vigilance is increased in the management of patients with Good's syndrome and CVID during the COVID-19 pandemic.

Serology-based therapeutic strategy in SARS-CoV-2-infected patients

SARS-CoV-2 infection can be a life-threatening disease. The optimal treatment of patients is not yet standardized. We use a serology-based therapeutic strategy based on the presence of antibodies against the SARS-CoV-2 virus, in which patients with positive serology receive aggressive anti-inflammatory treatment with high-dose dexamethasone and/or tocilizumab and patients with negative serology receive early convalescent plasma therapy. We also analyze the immunological impact of this therapy in the recovery of T cells, B cells and NK cells during hospitalization in a COVID-19 infectious ward. Our results suggest that aggressive therapy with early administration of convalescent plasma and high-dose dexamethasone may be of benefit in patients with SARS-CoV-2 infection and might avoid progression of lung damage or need of admission in intensive care. This strategy did not impair immune responses against SARS-CoV-2, as 93% of the patients generated antibodies against the virus. Independently of previous immunological status of the patients, serology-guided therapy might benefit even patients with a high CIRS-G score, immunosuppressed or medically debilitated individuals and elderly patients. T cell disturbances were most frequent in patients who required high-dose dexamethasone, and B cell depletion was most frequent in patients who received tocilizumab. Early passive immunotherapy with convalescent plasma does not affect lymphoid recovery.

Access to and safety of COVID-19 convalescent plasma in the United States Expanded Access Program: A national registry study

BACKGROUND

The United States (US) Expanded Access Program (EAP) to coronavirus disease 2019 (COVID-19) convalescent plasma was initiated in response to the rapid spread of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), the causative agent of COVID-19. While randomized clinical trials were in various stages of development and enrollment, there was an urgent need for widespread access to potential therapeutic agents. The objective of this study is to report on the demographic, geographical, and chronological characteristics of patients in the EAP, and key safety metrics following transfusion of COVID-19 convalescent plasma.

METHODS AND FINDINGS

Mayo Clinic served as the central institutional review board for all participating facilities, and any US physician could participate as a local physician-principal investigator. Eligible patients were hospitalized, were aged 18 years or older, and had-or were at risk of progression to-severe or life-threatening COVID-19; eligible patients were enrolled through the EAP central website. Blood collection facilities rapidly implemented programs to collect convalescent plasma for hospitalized patients with COVID-19. Demographic and clinical characteristics of all enrolled patients in the EAP were summarized. Temporal patterns in access to COVID-19 convalescent plasma were investigated by comparing daily and weekly changes in EAP enrollment in response to changes in infection rate at the state level. Geographical analyses on access to convalescent plasma included assessing EAP enrollment in all national hospital referral regions, as well as assessing enrollment in metropolitan areas and less populated areas that did not have access to COVID-19 clinical trials. From April 3 to August 23, 2020, 105,717 hospitalized patients with severe or life-threatening COVID-19 were enrolled in the EAP. The majority of patients were 60 years of age or older (57.8%), were male (58.4%), and had overweight or obesity (83.8%). There was substantial inclusion of minorities and underserved populations: 46.4% of patients were of a race other than white, and 37.2% of patients were of Hispanic ethnicity. Chronologically and geographically, increases in the number of both enrollments and transfusions in the EAP closely followed confirmed infections across all 50 states. Nearly all national hospital referral regions enrolled and transfused patients in the EAP, including both in metropolitan and in less populated areas. The incidence of serious adverse events was objectively low (<1%), and the overall crude 30-day mortality rate was 25.2% (95% CI, 25.0% to 25.5%). This registry study was limited by the observational and pragmatic study design that did not include a control or comparator group; thus, the data should not be used to infer definitive treatment effects.

CONCLUSIONS

These results suggest that the EAP provided widespread access to COVID-19 convalescent plasma in all 50 states, including for underserved racial and ethnic minority populations. The study design of the EAP may serve as a model for future efforts when broad access to a treatment is needed in response to an emerging infectious disease.

TRIAL REGISTRATION

ClinicalTrials.gov NCT#: NCT04338360.

Modelling the concentration of anti-SARS-CoV-2 immunoglobulin G in intravenous immunoglobulin product batches

Background

Plasma-derived intravenous immunoglobulin (IVIg) products contain a dynamic spectrum of immunoglobulin (Ig) G reactivities reflective of the donor population from which they are derived. We sought to model the concentration of anti-severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) IgG which could be expected in future plasma pool and final-product batches of CSL Behring’s immunoglobulin product Privigen.

Study design and methods

Data was extracted from accessible databases, including the incidence of coronavirus disease 2019 and SARS-CoV-2 vaccination status, antibody titre in convalescent and vaccinated groups and antibody half-life. Together, these parameters were used to create an integrated mathematical model that could be used to predict anti-SARS-CoV-2 antibody levels in future IVIg preparations.

Results

We predict that anti-SARS-CoV-2 IgG concentration will peak in batches produced in mid-October 2021, containing levels in the vicinity of 190-fold that of the mean convalescent (unvaccinated) plasma concentration. An elevated concentration (approximately 35-fold convalescent plasma) is anticipated to be retained in batches produced well into 2022. Measurement of several Privigen batches using the Phadia^™ EliA^™ SARS-CoV-2-Sp1 IgG binding assay confirmed the early phase of this model.

Conclusion

The work presented in this paper may have important implications for physicians and patients who use Privigen for indicated diseases.

Therapeutic Use of Convalescent Plasma in COVID-19 Infected Patients with Concomitant Hematological Disorders

The use of convalescent plasma (CP) from individuals recovered from severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is a promising therapeutic modality for the coronavirus disease 2019 (COVID-19). CP has been in use for at least a century to provide passive immunity against a number of diseases, and was recently proposed by the World Health Organization for human Ebola virus infection. Only a few small studies have so far been published on patients with COVID-19 and concomitant hematological malignancies (HM). The Italian Hematology Alliance on HM and COVID-19 has found that HM patients with COVID-19 clinically perform more poorly than those with either HM or COVID-19 alone. A COVID-19 infection in patients with B-cell lymphoma is associated with impaired generation of neutralizing antibody titers and lowered clearance of SARS-CoV-2. Treatment with CP was seen to increase antibody titers in all patients and to improve clinical response in 80% of patients examined. However, a recent study has reported impaired production of SARS-CoV-2-neutralizing antibodies in an immunosuppressed individual treated with CP, possibly supporting the notion of virus escape, particularly in immunocompromised individuals where prolonged viral replication occurs. This may limit the efficacy of CP treatment in at least some HM patients. More recently, it has been shown that CP may provide a neutralising effect against B.1.1.7 and other SARS-CoV-2 variants, thus expanding its application in clinical practice. More extensive studies are needed to further assess the use of CP in COVID-19-infected HM patients.

Early high-titer convalescent plasma therapy in patients with moderate and severe COVID-19

BACKGROUND AND OBJECTIVES

The use of COVID-19 convalescent plasma (CCP) has been approved by the FDA. We assessed the outcome of patients with moderate and severe COVID-19 following convalescent plasma therapy and the association with variables such as antibody titer in CCP units and transfusion time.

MATERIALS AND METHODS

In this prospective cohort study, 3097 patients with moderate and severe COVID-19 (according to WHO Progression Scale) had heterogeneous demographic and clinical characteristics received plasma with an unknown titer at the transfusion time. Firstly, information about age, sex, blood group, the time interval from hospitalization to CCP transfusion, underlying disease, and antibody titer with the outcome were investigated. Then, multivariate logistic regression and area under the curve (AUC) were performed for the association between disease severity and intubation variables with transfusion time and outcome.

RESULTS

Patients with younger age receiving CCP in the first five days of hospitalization had lower mortality (P < 0.0001). Moreover, patients without the underlying disease had lower mortality (P < 0.001). The mortality rate also decreased in severe patients who were intubated receiving CCP for less than five days (P < 0.001). In patients with moderate severity (score less than 5) who received IgG antibody levels above 1:320 in less than five days had lower mortality (P < 0.0001).

CONCLUSION

Our findings suggested that COVID-19 patients with the moderate type of disease receiving CCP units with high antibody titers in the early stages of the disease experienced greater effectiveness of CCP therapy.

Early Convalescent Plasma for High-Risk Outpatients with Covid-19

BACKGROUND

Early administration of convalescent plasma obtained from blood donors who have recovered from coronavirus disease 2019 (Covid-19) may prevent disease progression in acutely ill, high-risk patients with Covid-19.

METHODS

In this randomized, multicenter, single-blind trial, we assigned patients who were being treated in an emergency department for Covid-19 symptoms to receive either one unit of convalescent plasma with a high titer of antibodies against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) or placebo. All the patients were either 50 years of age or older or had one or more risk factors for disease progression. In addition, all the patients presented to the emergency department within 7 days after symptom onset and were in stable condition for outpatient management. The primary outcome was disease progression within 15 days after randomization, which was a composite of hospital admission for any reason, seeking emergency or urgent care, or death without hospitalization. Secondary outcomes included the worst severity of illness on an 8-category ordinal scale, hospital-free days within 30 days after randomization, and death from any cause.

RESULTS

A total of 511 patients were enrolled in the trial (257 in the convalescent-plasma group and 254 in the placebo group). The median age of the patients was 54 years; the median symptom duration was 4 days. In the donor plasma samples, the median titer of SARS-CoV-2 neutralizing antibodies was 1:641. Disease progression occurred in 77 patients (30.0%) in the convalescent-plasma group and in 81 patients (31.9%) in the placebo group (risk difference, 1.9 percentage points; 95% credible interval, -6.0 to 9.8; posterior probability of superiority of convalescent plasma, 0.68). Five patients in the plasma group and 1 patient in the placebo group died. Outcomes regarding worst illness severity and hospital-free days were similar in the two groups.

CONCLUSIONS

The administration of Covid-19 convalescent plasma to high-risk outpatients within 1 week after the onset of symptoms of Covid-19 did not prevent disease progression. (SIREN-C3PO ClinicalTrials.gov number, NCT04355767.).

Assessment of anti-SARS-CoV-2 antibodies level in convalescents plasma

Despite extensive vaccination, the quantity of patients infected with the SARS-CoV-2 virus and its variants continues to grow worldwide. Treating patients with a severe course of COVID-19 is a difficult challenge. One of the generally accepted and specific therapy methods is the use of plasma rich in anti-SARS-CoV-2 antibodies. On the other hand, assessing the antibodies level depending on the time after infection allows for vaccine-decision. The study marked the level of anti-SARS-CoV-2 IgG antibodies in 351 COVID-19 convalescent residents of one geographical region in Poland. The study group included blood donors. The studies were cross-sectional and extended to a questionnaire to determine infection severity. These data were compiled statistically. The study considered epidemiological factors, the time from the end of the infection, and infection severity. The fastest increase of the antibodies level was observed up to 59 days after COVID-19, and it was statistically significantly higher among men. Higher levels of antibodies were found among people above the average age in both men and women. There was an increase in the level of antibodies since the onset of the disease in men, while in women, it decreased. The antibodies level was also found to depend on the severity of the course of COVID-19 infection. The optimal group of plasma donors in the studied geographical region is men and women above 39 years old. after a more severe infection. The titer of antibodies increases with time from the disease.

Antibody response against SARS-CoV-2 in convalescent plasma donors: can we predict subjects' eligibility?

Introduction

As the Coronavirus Disease 2019 (COVID-19) pandemic unfolds around the world; answers related to the antibody response against the virus are necessary to develop treatment and prophylactic strategies. We attempted to understand part of the immune response of convalescent plasma donation candidates.

Method

We carried out a cross-sectional, observational, non-intervention study, testing 102 convalescent plasma donation candidates for antibodies against the virus, relating these data to the time interval between symptom onset and sample collection, age, disease severity, and gender.

Results

In our sample, the individuals who developed a greater antibody response were the ones who had a longer time interval between symptom onset and sample collection, the ones who had been hospitalized and the subjects above 35 years old. Moreover, 17 individuals did not present any reactive antibodies.

Conclusion

These results are important in that they raise questions about the role of the humoral response against the virus, as some individuals do not develop antibodies to fight it. In addition, they help develop recruitment strategies for convalescent plasma donors, who should be asymptomatic for at least 21 days and are possibly more likely to have reactive antibodies after 35 days without symptoms.

Building a better antibody through the Fc: advances and challenges in harnessing antibody Fc effector functions for antiviral protection

Antibodies can provide antiviral protection through neutralization and recruitment of innate effector functions through the Fc domain. While neutralization has long been appreciated for its role in antibody-mediated protection, a growing body of work indicates that the antibody Fc domain also significantly contributes to antiviral protection. Recruitment of innate immune cells such as natural killer cells, neutrophils, monocytes, macrophages, dendritic cells and the complement system by antibodies can lead to direct restriction of viral infection as well as promoting long-term antiviral immunity. Monoclonal antibody therapeutics against viruses are increasingly incorporating Fc-enhancing features to take advantage of the Fc domain, uncovering a surprising breadth of mechanisms through which antibodies can control viral infection. Here, we review the recent advances in our understanding of antibody-mediated innate immune effector functions in protection from viral infection and review the current approaches and challenges to effectively leverage innate immune cells via antibodies.

Clinical trials with antiviral drugs against COVID-19: some progress and many shattered hopes

Vaccines and drugs are the cornerstones in the fight against the SARS-CoV-2 pandemic. While vaccines were a success story, the development of antiviral drugs against SARS-CoV-2 turned out to be difficult. For an accelerated use of antivirals in the clinic, most SARS-CoV-2 antivirals represented repurposed drugs. The present article summarizes the outcomes of clinical trials with antiviral drugs in COVID-19 patients. Many antiviral drugs failed to demonstrate beneficial effects or showed mixed results. One reason for the low success rate of clinical trials was shortcomings of antiviral tests in cell culture systems and another reason was the abundance of ill-coordinated and underpowered clinical trials. However, large pragmatic clinical trials particularly of the British RECOVERY trial series demonstrated that even under emergency situation drug trials can be conducted in a timely way such that the therapy of COVID-19 patients can be based on evidence basis instead on expert opinion or even worse on political pressure.

Randomisierte Studien zum Einsatz von Rekonvaleszentenplasma bei COVID-19: eine Standortbestimmung

Plasma von genesenen Spendern mit COVID-19 (COVID-19 Convalescent Plasma, CCP) wurde als Behandlungsoption für Patienten mit COVID-19 in Betracht gezogen. In der ersten Phase der Pandemie wurden mehrere Fallberichte und Fallkontrollstudien mit Hinweisen auf eine therapeutische Wirkung veröffentlicht. Inzwischen liegen die Ergebnisse zahlreicher randomisierter Studien vor. Die Studien unterscheiden sich in vielen Aspekten, u. a. in den Patientenpopulationen, die von ambulanten Patienten mit mildem COVID-19 bis zu kritisch Kranken reichten, wie auch den Endpunkten. Ebenso war der Behandlungsstandard innerhalb der klinischen Studien sehr unterschiedlich. Vor allem aber unterschied sich das Prüfpräparat CCP erheblich in Bezug auf das Behandlungsschema, das Volumen und den Gehalt an Antikörpern. Im Folgenden werden wir die Ergebnisse der bisher publizierten randomisierten Studien diskutieren. Aus den bisher veröffentlichten Ergebnissen lässt sich eine Wirksamkeit von CCP ableiten, sofern es sehr hohe Titer neutralisierender Antikörper enthält und früh im Krankheitsverlauf verabreicht wird. COVID-19-Rekonvaleszenten-Plasma ist noch keine Routinebehandlung und sollte möglichst weiter in klinischen Studien untersucht werden. Neu konzipierte Studien sollten sich auf die frühe Anwendung von CCP mit einem hohen Gehalt an neutralisierenden Antikörpern bei Patienten mit hohem Risiko für eine Progression zu einer schweren COVID-19-Erkrankung konzentrieren und wichtige Begleitmedikationen kontrollieren.

COVID-19 pandemic. What have we learned?

Since the COVID-19 pandemic was declared in March 2020, we have learned a lot about the SARS-CoV-2 coronavirus, and its role in pediatric pathology. Children are infected in a rate quite similar to adults, although in most cases they suffer mild or asymptomatic symptoms. Around 1% of those infected require hospitalization, less than 0.02% require intensive care, and mortality is very low and generally in children with comorbidities. The most common clinical diagnoses are upper or lower respiratory infections, gastrointestinal infection and, more seriously, multisystemic inflammatory syndrome (MIS-C). Most episodes do not require treatment, except for MIS-C. Remdesivir has been widely used as a compassionate treatment and its role has yet to be defined. The newborn can become infected, although vertical transmission is very low (<1%) and it has been shown that the baby can safely cohabit with its mother and be breastfed. In general, neonatal infections have been mild. Primary care has supported a very important part of the management of the pandemic in pediatrics. There has been numerous collateral damage derived from the difficulty of access to care and the isolation suffered by children. The mental health of the pediatric population has been seriously affected. Although it has been shown that schooling has not led to an increase in infections, but rather the opposite. It is essential to continue maintaining the security measures that make schools a safe place, so necessary not only for children's education, but for their health in general.

[COVID-19 pandemic. What have we learned?]

Since the COVID-19 pandemic was declared in March 2020, we have learned a lot about the SARS-CoV-2 coronavirus, and its role in pediatric pathology.Children are infected in a rate quite similar to adults, although in most cases they suffer mild or asymptomatic symptoms. Around 1% of those infected require hospitalization, less than 0.02% require intensive care, and mortality is very low and generally in children with comorbidities. The most common clinical diagnoses are upper or lower respiratory infections, gastrointestinal infection and, more seriously, multisystemic inflammatory syndrome (MIS-C). Most episodes do not require treatment, except for MIS-C. Remdesivir has been widely used as a compassionate treatment and its role has yet to be defined.The newborn can become infected, although vertical transmission is very low (<1%) and it has been shown that the baby can safely cohabit with its mother and be breastfed. In general, neonatal infections have been mild.Primary care has supported a very important part of the management of the pandemic in pediatrics. There has been numerous collateral damage derived from the difficulty of access to care and the isolation suffered by children. The mental health of the pediatric population has been seriously affected. Although it has been shown that schooling has not led to an increase in infections, but rather the opposite. It is essential to continue maintaining the security measures that make schools a safe place, so necessary not only for children's education, but for their health in general.

A hitchhiker's guide through the COVID-19 galaxy

Numerous reviews have summarized the epidemiology, pathophysiology and the various therapeutic aspects of Coronavirus disease 2019 (COVID-19), but a practical guide on "how to treat whom with what and when" based on an understanding of the immunological background of the disease stages remains missing. This review attempts to combine the current knowledge about the immunopathology of COVID-19 with published evidence of available and emerging treatment options. We recognize that the information about COVID-19 and its treatment is rapidly changing, but hope that this guide offers those on the frontline of this pandemic an understanding of the host response in COVID-19 patients and supports their ongoing efforts to select the best treatments tailored to their patient's clinical status.

Effect of High-Titer Convalescent Plasma on Progression to Severe Respiratory Failure or Death in Hospitalized Patients With COVID-19 Pneumonia: A Randomized Clinical Trial

IMPORTANCE

Convalescent plasma (CP) has been generally unsuccessful in preventing worsening of respiratory failure or death in hospitalized patients with COVID-19 pneumonia.

OBJECTIVE

To evaluate the efficacy of CP plus standard therapy (ST) vs ST alone in preventing worsening respiratory failure or death in patients with COVID-19 pneumonia.

DESIGN, SETTING, AND PARTICIPANTS

This prospective, open-label, randomized clinical trial enrolled (1:1 ratio) hospitalized patients with COVID-19 pneumonia to receive CP plus ST or ST alone between July 15 and December 8, 2020, at 27 clinical sites in Italy. Hospitalized adults with COVID-19 pneumonia and a partial pressure of oxygen-to-fraction of inspired oxygen (Pao2/Fio2) ratio between 350 and 200 mm Hg were eligible.

INTERVENTIONS

Patients in the experimental group received intravenous high-titer CP (≥1:160, by microneutralization test) plus ST. The volume of infused CP was 200 mL given from 1 to a maximum of 3 infusions. Patients in the control group received ST, represented by remdesivir, glucocorticoids, and low-molecular weight heparin, according to the Agenzia Italiana del Farmaco recommendations.

MAIN OUTCOMES AND MEASURES

The primary outcome was a composite of worsening respiratory failure (Pao2/Fio2 ratio <150 mm Hg) or death within 30 days from randomization.

RESULTS

Of the 487 randomized patients (241 to CP plus ST; 246 to ST alone), 312 (64.1%) were men; the median (IQR) age was 64 (54.0-74.0) years. The modified intention-to-treat population included 473 patients. The primary end point occurred in 59 of 231 patients (25.5%) treated with CP and ST and in 67 of 239 patients (28.0%) who received ST (odds ratio, 0.88; 95% CI, 0.59-1.33; P = .54). Adverse events occurred more frequently in the CP group (12 of 241 [5.0%]) compared with the control group (4 of 246 [1.6%]; P = .04).

CONCLUSIONS AND RELEVANCE

In patients with moderate to severe COVID-19 pneumonia, high-titer anti-SARS-CoV-2 CP did not reduce the progression to severe respiratory failure or death within 30 days.

TRIAL REGISTRATION

ClinicalTrials.gov Identifier: NCT04716556.

Structural Basis of a Human Neutralizing Antibody Specific to the SARS-CoV-2 Spike Protein Receptor-Binding Domain

The emerging new lineages of severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) have marked a new phase of coronavirus disease 2019 (COVID-19). Understanding the recognition mechanisms of potent neutralizing monoclonal antibodies (NAbs) against the spike protein is pivotal for developing new vaccines and antibody drugs. Here, we isolated several monoclonal antibodies (MAbs) against the SARS-CoV-2 spike protein receptor-binding domain (S-RBD) from the B cell receptor repertoires of a SARS-CoV-2 convalescent. Among these MAbs, the antibody nCoV617 demonstrates the most potent neutralizing activity against authentic SARS-CoV-2 infection, as well as prophylactic and therapeutic efficacies against the human angiotensin-converting enzyme 2 (ACE2) transgenic mouse model in vivo. The crystal structure of S-RBD in complex with nCoV617 reveals that nCoV617 mainly binds to the back of the "ridge" of RBD and shares limited binding residues with ACE2. Under the background of the S-trimer model, it potentially binds to both "up" and "down" conformations of S-RBD. In vitro mutagenesis assays show that mutant residues found in the emerging new lineage B.1.1.7 of SARS-CoV-2 do not affect nCoV617 binding to the S-RBD. These results provide a new human-sourced neutralizing antibody against the S-RBD and assist vaccine development. IMPORTANCE COVID-19 is a respiratory disease caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). The COVID-19 pandemic has posed a serious threat to global health and the economy, so it is necessary to find safe and effective antibody drugs and treatments. The receptor-binding domain (RBD) in the SARS-CoV-2 spike protein is responsible for binding to the angiotensin-converting enzyme 2 (ACE2) receptor. It contains a variety of dominant neutralizing epitopes and is an important antigen for the development of new coronavirus antibodies. The significance of our research lies in the determination of new epitopes, the discovery of antibodies against RBD, and the evaluation of the antibodies' neutralizing effect. The identified antibodies here may be drug candidates for the development of clinical interventions for SARS-CoV-2.

Elevated cytokines and chemokines in peripheral blood of patients with SARS-CoV-2 pneumonia treated with high-titer convalescent plasma

The global SARS-CoV-2 coronavirus pandemic continues to be devastating in many areas. Treatment options have been limited and convalescent donor plasma has been used by many centers to transfer passive neutralizing antibodies to patients with respiratory involvement. The results often vary by institution and are complicated by the nature and quality of the donor plasma itself, the timing of administration and the clinical aspects of the recipients. SARS-CoV-2 infection is known to be associated with an increase in the blood concentrations of several inflammatory cytokines/chemokines, as part of the overall immune response to the virus and consequential to mediated lung pathology. Some of these correlates contribute to the cytokine storm syndrome and acute respiratory distress syndrome, often resulting in fatality. A Phase IIa clinical trial at our institution using high neutralizing titer convalescent plasma transfer gave us the unique opportunity to study the elevations of correlates in the first 10 days after infusion. Plasma recipients were divided into hospitalized COVID-19 pneumonia patients who did not (Track 2) or did (Track 3) require mechanical ventilation. Several cytokines were elevated in the patients of each Track and some continued to rise through Day 10, while others initially increased and then subsided. Furthermore, elevations in MIP-1α, MIP-1β and CRP correlated with disease progression of Track 2 recipients. Overall, our observations serve as a foundation for further study of these correlates and the identification of potential biomarkers to improve upon convalescent plasma therapy and to drive more successful patient outcomes.

COVID-19, the disease caused by the SARS-CoV-2 virus, has a varied clinical course with limited treatment options. While some patients mount a productive immune response leading to recovery, others progress to rapid respiratory deterioration that may require hospitalization and mechanical ventilation. Our institution conducted a clinical trial to evaluate the efficacy of convalescent plasma therapy (CPT) to treat patients hospitalized with COVID-19 pneumonia. In this arm of the study, we sought to examine immune analytes in donor plasma as well as evaluate the recipients’ plasma before CPT infusion, and at Day 3 and Day 10 post-CPT infusion. We found some analytes to be elevated in plasma donors, compared to healthy controls, even after recovery. Plasma composition in CPT recipients prior to infusion showed elevations in several analytes associated with immune activation. Some significant differences were seen in plasma composition in patients in our Track 2 cohort (hospitalized without mechanical ventilation) compared to the Track 3 cohort (hospitalized with mechanical ventilation). In addition, we obtained plasma samples for hospitalized COVID-19 patients that did not receive CPT and noted several differences in the course of immune analyte production over time compared to the CPT-treated patients.

COVID-19 Advanced Care

The coronavirus disease 2019 (COVID-19) pandemic, related to the novel severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), has caused a worldwide sudden and substantial burden in public health due to an enormous increase in hospitalizations for pneumonia with the multiorgan disease. Treatment for individuals with COVID-19 includes best practices for supportive management of acute hypoxic respiratory failure. Emerging data indicate that dexamethasone therapy reduces 28-day mortality in patients requiring supplemental oxygen compared with usual care, and ongoing trials are testing the efficacy of antiviral therapies, immune modulators and anticoagulants in the prevention of disease progression and complications, while monoclonal antibodies and hyperimmune globulin may provide additional preventive strategies. Consensus suggestions can standardize care, thereby improving outcomes and facilitating future research. This review discusses current evidence regarding the pharmacotherapy of COVID-19.

COVID-19 Convalescent plasma

As the coronavirus disease (COVID-19) pandemic led to a global health crisis, there were limited treatment options and no prophylactic therapies for those exposed to Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2). Convalescent plasma is quick to implement, potentially provides benefits, and has a good safety profile. The therapeutic potential of COVID-19 convalescent plasma (CCP) is likely mediated by antibodies through direct viral neutralization and Fc-dependent functions such as a phagocytosis, complement activation, and antibody-dependent cellular cytotoxicity. In the United States, CCP became one of the most common treatments with over half million units transfused despite limited efficacy data. More than a dozen randomized trials now demonstrate that CCP does not provide benefit for those with moderate to severe disease. However, similar to other passive antibody therapies, CCP is beneficial for early disease, when provided to elderly outpatients within 72 hours after symptom onset. Only high-titer CCP should be transfused. CCP should also be considered for immunosuppressed COVID-19 patients. CCP collected in proximity, by time and location, to the patient may be more beneficial due to SARS-CoV-2 variants. Additional randomized trial data are still accruing and should be incorporated with other trial data to optimize CCP indications.

Active surveillance of serious adverse events following transfusion of COVID-19 convalescent plasma

Background

The reported incidence of adverse reactions following Coronavirus disease 2019 (COVID‐19) convalescent plasma (CCP) transfusion has generally been lower than expected based on the incidence of transfusion reactions that have been observed in studies of conventional plasma transfusion. This raises the concern for under‐reporting of adverse events in studies of CCP that rely on passive surveillance strategies.

Materials and Methods

Our institution implemented a protocol to actively identify possible adverse reactions to CCP transfusion. In addition, we retrospectively reviewed the charts of inpatients who received CCP at Stanford Hospital between May 13, 2020 and January 31, 2021. We determined the incidence of adverse events following CCP transfusion.

Results

A total of 49 patients received CCP. Seven patients (14%) had an increased supplemental oxygen requirement within 4 h of transfusion completion, including one patient who was intubated during the transfusion. An additional 11 patients (total of 18, 37%) had increased oxygen requirements within 24 h of transfusion, including 3 patients who were intubated. Six patients (12%) fulfilled criteria for transfusion‐associated circulatory overload (TACO).

Conclusion

Using an active surveillance strategy, we commonly observed adverse events following the transfusion of CCP to hospitalized patients. It was not possible to definitively determine whether or not these adverse events are related to CCP transfusion. TACO was likely over‐diagnosed given overlap with the manifestations of COVID‐19. Nevertheless, these results suggest that the potential adverse effects of CCP transfusion may be underestimated by reports from passive surveillance studies.

Complex Pathophysiological Mechanisms and the Propose of the Three-Dimensional Schedule For Future COVID-19 Treatment

At present, the global COVID-19 epidemic is still in a state of anxiety, and increasing the cure rate of critically ill patients is an important means to defeat the virus. From an immune perspective, ARDS driven by an inflammatory storm is still the direct cause of death in severe COVID-19 patients. Although some experience has been gained in the treatment of COVID-19, and intensive COVID-19 vaccination has been carried out recently, it is still effective to save lives to develop more effective programs to alleviate the inflammatory storm and ARDS in patients with SARS-CoV-2 or emerging variants of SARS-CoV-2. In reorganizing the ARDS-related inflammatory storm formation program in COVID-19 patients, we highlighted the importance of the vicious circle of inflammatory cytokines and inflammatory cell death, which is aggravated by blood circulation to form multi-system inflammation. Summarizes the interlocking and crisscrossing of inflammatory response and inflammatory cell death mechanisms including NETs, pyrolysis, apoptosis and PANoptosis in severe COVID-19. More importantly, in response to the inflammatory storm formation program we described, and on the premise of following ethical and clinical experimental norms, we propose a three-dimensional integrated program for future research based on boosting antiviral immune response at the initial stage, inhibiting inflammatory cytokine signaling at the exacerbation stage and inhibiting cell death before it's worse to prevent and alleviate ARDS.

Convalescent plasma treatment for patients of 80 years and older with COVID-19 pneumonia

BACKGROUND

Older patients, frequently with multiple comorbidities, have a high mortality from COVID-19 infection. Convalescent plasma (CP) is a therapeutic option for these patients. Our objective is to retrospectively evaluate the efficacy and adverse events of CP treatment in this population group.

METHODS

Forty one patients over 80 years old with COVID-19 pneumonia received CP added to standard treatment, 51.2% with high anti-SARS-CoV-2 IgG titers and 48.8% with low titers. Median time between the onset of symptoms and the infusion of plasma was 7 days (IQR 4-10). A similar group of 82 patients who received only standard treatment, during a period in which CP was not available, were selected as a control group.

RESULTS

In-hospital mortality was 26.8% for controls and 14.6% for CP patients (P = 0.131) and ICU admission was 8.5% for controls and 4.9% for CP patients (P = 0.467). Mortality tended to be lower in the high-titer group (9.5%) than in the low-titer group (20%), and in patients transfused within the first 7 days of symptom onset (10%) than in patients transfused later (19.1%), although the differences were not statistically significant (P = 0.307 and P = 0.355 respectively). There was no difference in the length of hospitalization. No significant adverse events were associated with CP treatment.

CONCLUSIONS

Convalescent plasma treatment in patients over 80 years old with COVID-19 pneumonia was well tolerated but did not present a statistically significant difference in hospital mortality, ICU admission, or length of hospitalization. The results should be interpreted with caution as only half the patients received high-titer CP and the small number of patients included in the study limits the statistical power to detect significant differences.

TRIAL REGISTRATION

CEIm Cantabria # 2020.127.

Results of the CAPSID randomized trial for high-dose convalescent plasma in patients with severe COVID-19

BACKGROUNDCOVID-19 convalescent plasma (CCP) has been considered a treatment option for COVID-19. This trial assessed the efficacy of a neutralizing antibody containing high-dose CCP in hospitalized adults with COVID-19 requiring respiratory support or intensive care treatment.METHODSPatients (n = 105) were randomized 1:1 to either receive standard treatment and 3 units of CCP or standard treatment alone. Control group patients with progress on day 14 could cross over to the CCP group. The primary outcome was a dichotomous composite outcome of survival and no longer fulfilling criteria for severe COVID-19 on day 21.ResultsThe primary outcome occurred in 43.4% of patients in the CCP group and 32.7% in the control group (P = 0.32). The median time to clinical improvement was 26 days in the CCP group and 66 days in the control group (P = 0.27). The median time to discharge from the hospital was 31 days in the CCP group and 51 days in the control group (P = 0.24). In the subgroup that received a higher cumulative amount of neutralizing antibodies, the primary outcome occurred in 56.0% of the patients (vs. 32.1%), with significantly shorter intervals to clinical improvement (20 vs. 66 days, P < 0.05) and to hospital discharge (21 vs. 51 days, P = 0.03) and better survival (day-60 probability of survival 91.6% vs. 68.1%, P = 0.02) in comparison with the control group.ConclusionCCP added to standard treatment was not associated with a significant improvement in the primary and secondary outcomes. A predefined subgroup analysis showed a significant benefit of CCP among patients who received a larger amount of neutralizing antibodies.Trial registrationClinicalTrials.gov NCT04433910.FundingBundesministerium für Gesundheit (German Federal Ministry of Health): ZMVI1-2520COR802.

Convalescent plasma associates with reduced mortality and improved clinical trajectory in patients hospitalized with COVID-19

BACKGROUNDEvidence supporting convalescent plasma (CP), one of the first investigational treatments for coronavirus disease 2019 (COVID-19), has been inconclusive, leading to conflicting recommendations. The primary objective was to perform a comparative effectiveness study of CP for all-cause, in-hospital mortality in patients with COVID-19.METHODSThe multicenter, electronic health records-based, retrospective study included 44,770 patients hospitalized with COVID-19 in one of 176 HCA Healthcare-affiliated community hospitals. Coarsened exact matching (1:k) was employed, resulting in a sample of 3774 CP and 10,687 comparison patients.RESULTSExamination of mortality using a shared frailty model, controlling for concomitant medications, date of admission, and days from admission to transfusion, demonstrated a significant association of CP with lower mortality risk relative to the comparison group (adjusted hazard ratio [aHR] = 0.71; 95% CI, 0.59-0.86; P < 0.001). Examination of patient risk trajectories, represented by 400 clinico-demographic features from our real-time risk model (RTRM), indicated that patients who received CP recovered more quickly. The stratification of days to transfusion revealed that CP within 3 days after admission, but not within 4 to 7 days, was associated with a significantly lower mortality risk (aHR = 0.53; 95% CI, 0.47-0.60; P < 0.001). CP serology level was inversely associated with mortality when controlling for its interaction with days to transfusion (HR = 0.998; 95% CI, 0.997-0.999; P = 0.013), yet it did not reach univariable significance.CONCLUSIONSThis large, diverse, multicenter cohort study demonstrated that CP, compared with matched controls, is significantly associated with reduced risk of in-hospital mortality. These observations highlight the utility of real-world evidence and suggest the need for further evaluation prior to abandoning CP as a viable therapy for COVID-19.FUNDINGThis research was supported in whole by HCA Healthcare and/or an HCA Healthcare-affiliated entity, including Sarah Cannon and Genospace.