The unmet need for COVID-19 treatment in immunocompromised patients.

BACKGROUND: Immunocompromised (IC) patients are at increased risk of severe and/or prolonged COVID-19. MAIN TEXT: The recent study by Scaglione et al., addresses the issue of IC outpatients with SARS-CoV-2 infection. Authors describe the real-life use of SARS-CoV-2 antivirals and/or monoclonal antibodies and the clinical benefit in high-risk COVID-19 patients. The study supports the use of early combination therapy in a subgroup of extremely high risk patients, and considers the combined strategy as a gold standard regimen to both increase the effectiveness of early treatment, especially in IC individuals, and, reduce the emergence of SARS-CoV-2 escape mutants. CONCLUSION: A tailored and standardised therapeutic approach in case of IC out and inpatients with SARS-CoV-2 infection is needed.

Covid-19: All facts, no myth

On December 31, 2019, the China Health Authority alerted WHO about 27 cases of pneumonia of unknown etiology in Wuhan City. It was subsequently named Severe Acute Respiratory Syndrome Coronavirus-2 (SARS-CoV-2) and the disease as Coronavirus Disease 2019 (COVID-19). The disease has now become pandemic. Current review was done to summarize information on COVID-19 published in various scientific works. Electronic databases containing medical articles viz., MEDLINE/PubMed, Google Scholar etc were searched using the Medical Subject Headings 'COVID-19', '2019-nCoV', 'coronavirus' and 'SARS-CoV-2' during antecedent one year. All study designs were incorporated to harvest clinical, laboratory, imaging, and hospital course data. The intermediate host of the virus is still unknown. Respiratory droplets produced by the patient is main source of transmission. SARS-CoV-2 invades the airway epithelium by binding to angiotensin-converting enzyme-2 (ACE2) receptor with Coronavirus spike (S) protein. Most common symptoms are fever (98%), dry cough (77%), and dyspnea (63.5%). Later, complications like acute respiratory distress syndrome, septic shock etc may occur. Advanced age and co-morbidities like Diabetes have higher mortality otherwise Case Fatality Rate is 2-3%. RT-PCR is the diagnosis of choice. Since no universally accepted registered drug or FDA approved vaccine has come by now, prevention is the key. Hands should be regularly cleaned with soap or alcohol based sanitizer and in public, Nose and Mouth should be covered with face-mask and social distance of one meter should be maintained. While Vaccines are expected by early 2021, we should not forget to take comprehensive measures to prevent future outbreaks of zoonotic origin. Copyright © 2020, Kathmandu University. All rights reserved.

Pathogen reduction with methylene blue does not have an impact on the clinical effectiveness of COVID-19 convalescent plasma.

BACKGROUND AND OBJECTIVES: There is a concern about a possible deleterious effect of pathogen reduction (PR) with methylene blue (MB) on the function of immunoglobulins of COVID-19 convalescent plasma (CCP). We have evaluated whether MB-treated CCP is associated with a poorer clinical response compared to other inactivation systems at the ConPlas-19 clinical trial. MATERIALS AND METHODS: This was an ad hoc sub-study of the ConPlas-19 clinical trial comparing the proportion of patients transfused with MB-treated CCP who had a worsening of respiration versus those treated with amotosalen (AM) or riboflavin (RB). RESULTS: One-hundred and seventy-five inpatients with SARS-CoV-2 pneumonia were transfused with a single CCP unit. The inactivation system of the CCP units transfused was MB in 90 patients (51.4%), RB in 60 (34.3%) and AM in 25 (14.3%). Five out of 90 patients (5.6%) transfused with MB-treated CCP had worsening respiration compared to 9 out of 85 patients (10.6%) treated with alternative PR methods (p = 0.220). Of note, MB showed a trend towards a lower rate of respiratory progressions at 28 days (risk ratio, 0.52; 95% confidence interval, 0.18-1.50). CONCLUSION: Our data suggest that MB-treated CCP does not provide a worse clinical outcome compared to the other PR methods for the treatment of COVID-19.

SARS-COV-2 INFECTION WITH RITUXIMAB THERAPY

SESSION TITLE: COVID-19 Case Report Posters 3 SESSION TYPE: Case Report Posters PRESENTED ON: 10/19/2022 12:45 pm - 01:45 pm INTRODUCTION: Exposure to anti-CD20 treatment affects B cell functions involved in anti-COVID immunity and impacts the clinical course of infection. We present two patients with persistent respiratory symptoms and persistent SARS-COv-2 PCR positivity months after initial infection. The aim of presenting these cases is to highlight how exposure to Rituximab can result in patients having significantly prolonged SARS-CoV-2 infections that may require special treatment compared to immunocompetent patients. CASE PRESENTATION: Patient A is a 46-year-old man with a history of marginal zone lymphoma, who was treated with six cycles of bendamustine with rituximab and monthly maintenance rituximab. He has been hypoxic for 7 months after COVID infection with ground glass opacities on imaging, elevated CRP of 58.4, positive PCR, undetectable CD3/CD4 and low cycle threshold of 28, suggesting rapid active viral replication. COVID IGG was negative. T cell subsets counts were undetectable. IgG 351, IgA 59, IgM less than 10. He was treated with a 10-day course of Remdesevir and steroids. Given lack of humoral immunity, he was given convalescent plasma. At discharge he developed positive COVID IgG and remained COVID positive by PCR. He had complete resolution of hypoxia. Patient B is a 68-year-old man with a history of chronic lymphocytic leukemia, who was treated with six years of rituximab maintenance therapy, last rituximab was three years ago. He was diagnosed with SARS-CoV-2 three months prior to admission with worsening hypoxia. He remained PCR positive with persistent respiratory symptoms. At readmission his imaging showed ground glass opacities, CRP 6.6 and cycle threshold was 27.8. The follow studies were abnormally low:IgG 541, IgA 25, IgM 14, absolute CD3 171, absolute CD4 68. He was treated with remdesivir, steroids, granulocyte colony stimulating factor and sotrovimab. Despite these therapies, his hypoxia worsened, and he pursued comfort care. DISCUSSION: There are reports of patients receiving B cell depleting therapy who have persistent shedding of viable SARS-CoV. Persistent viral infection may be suspected in patients with relapsing symptoms, elevated CRP, D-dimer and active ground glass changes imaging. Low T cell subsets and low immunoglobulin levels indicate a CD20 related impairment of adaptive immunity. Time to viral clearance appears to be prolonged compared to general population in immunocompromised patients. There is some published experience using convalescent plasma in this setting. SARS-CoV-2 viremia has been demonstrated to predict adverse outcomes. Median cycle threshold has been shown to be lower, reflecting a high viral load comparable with acute infectious phase of COVID. CONCLUSIONS: To achieve stable clinical responses this subset of patients may benefit from early administration of combination regimens, including both passive immunotherapy and prolonged antiviral treatment. Reference #1: Furlan A, Forner G, Cipriani L, Vian E, Rigoli R, Gherlinzoni F, Scotton P. COVID-19 in B Cell-Depleted Patients After Rituximab: A Diagnostic and Therapeutic Challenge. Front Immunol. 2021 Nov 3;12:763412. doi: 10.3389/fimmu.2021.763412. PMID: 34804051;PMCID: PMC8595333. DISCLOSURES: No relevant relationships by Cheryl Augenstein Primary Investigator relationship with Boehringer Ingelheim Please note: 2/2022-2/2024 Added 04/01/2022 by A. Thanushi Wynn, value=Grant/Research Support

Human intramuscular hyperimmune gamma globulin (HIHGG) anti-SARS-CoV-2-Stability study

Background: At the beginning of the SARS-CoV-2 pandemic, there were no targeted methods for prevention of the new viral infection as well as no effective therapies to fight COVID-19. Numerous attempts were undertaken to apply both old and new therapeutic options. Among others, attention was focused on passive immunotherapy. Initially, transfusion of plasma from COVID-19 convalescents seemed promising. The highest neutralizing potential in convalescent plasma was determined in antibodies targeting SARS-CoV-2 spike protein. Several centersworldwide have undertaken the production of hyperimmune anti-SARS-CoV-2 immunoglobulin from convalescent plasma. In Poland, human intramuscular hyperimmune gamma globulin anti-SARS-CoV-2 (hIHGG anti-SARS-CoV-2) was produced within the project financed by the Medical Research Agency. It was fractionated from convalescent plasma donations using Cohn's method. As compared to convalescent plasma, the concentration of anti-SARS-CoV-2 IgG antibodies in hIHGGanti-SARS-CoV-2 was several folds higher. Aims: The study aim was to explore the stability of the IgG antibody titre targeting SARS-CoV-2 spike protein in hIHGG anti-SARS-CoV-2 during 17-month storage. Methods: IgG antibodies directed to the S1 protein titers were measured with Anti-SARS-CoV-2 ELISA (IgG) (EUROIMMUN)-for semiquantitative in vitro evaluation of anti-SARS-CoV-2. The test was used in 2020, and since December 2020 anti-SARS-CoV-2 QuantiVac ELISA (IgG) (EUROIMMUN) quantitative test was in use. Results: The tests were performed using the semi-quantitative method immediately after the production of hIHGG and up to 3 months of storage. The mean antibody titre was 49.6 RU/ml, CV = 8.1. The quantitative method was used for measurements from 2 to 17 months of storage. The mean antibody titre was 1780 BAU/ml CV = 6.4%. Summary/Conclusions: The analysis of IgG antibody titre targeting SARS-CoV-2 spike protein in hIHGG anti-SARS-CoV-2 revealed that during storage no statistically significant differences were observed in the antibodies titre. It can therefore be concluded that the obtained hIHGG anti-SARS-CoV-2 is a stable product.

Clinical Management of Patients With B-Cell Depletion Agents to Treat or Prevent Prolonged and Severe SARS-COV-2 Infection: Defining a Treatment Pathway.

Introduction: Immunocompromised patients with B-cell depletion agents are at risk for persistence and/or severe SARS-COV-2 infection. We describe a case series of 21 COVID-19 patients under B cell depletion therapy, mostly treated with a combined therapy based on intravenous remdesevir (RDV) and steroid associated with SARS-CoV-2 monoclonal antibodies against Spike glycoprotein and/or hyper-immune convalescent plasma. Methods: This is a single-center longitudinal study. We retrospectively enrolled a total number of 21 B-cell depleted consecutive hospitalized patients with COVID-19 at the Lazzaro Spallanzani National Institute for Infectious Diseases, Rome, Italy, from November 2020 to December 2021. Demographic characteristics, medical history, clinical presentation, treatment, adverse drug reactions, and clinical and virological outcome were collected for all patients. In a subgroup, we explore immune T cells activation, T cells specific anti-SARS-COV-2 response, and neutralizing antibodies. Results: Twenty-one inpatients with B-cell depletion and SARS-COV-2 infection were enrolled. A median of 1 B cells/mm3 was detected. Eighteen patients presented hypogammaglobulinemia. All patients presented interstitial pneumonia treated with intravenous RDV and steroids. Sixteen patients were treated with monoclonal antibodies against SARS-CoV-2 Spike protein, four patients were treated with SARS-CoV-2 hyper-immune convalescent plasma infusion, and three patients received both treatments. A variable kinetic of T cell activation returning to normal levels at Day 30 after immunotherapy infusion was observed. All treated patients recovered. Conclusion: In COVID-19 immunosuppressed subjects, it is mandatory to establish a prompt, effective, and combined multi-target therapy including oxygen, antiviral, steroid, and antibody-based therapeutics, tailored to the patient's clinical needs.

Production and Quality Assurance of Human Polyclonal Hyperimmune Immunoglobulins Against SARS-CoV-2.

The coronavirus disease 2019 (COVID-19) pandemic has highlighted the potential therapeutic value of early passive polyclonal immunotherapy using high-titer convalescent plasma (CCP). Human polyclonal hyperimmune immunoglobulin (HIG) has several advantages over CCP. Unlike CCP, HIG can provide standardized and controlled antibody content. It is also subjected to robust pathogen reduction rendering it virally safe and is purified by technologies demonstrated to preserve immunoglobulin neutralization capacity and Fc fragment integrity. This document provides an overview of current practices and guidance for the collection and testing of plasma rich in antibodies against Severe Acute Respiratory Coronavirus 2 (SARS-CoV-2) and its industrial fractionation for the manufacture of quality-assured and safe HIG. Considerations are also given to the production of HIG preparations in low- and middle-income countries.

Efficient and Sustainable Platform for Preparation of a High-Quality Immunoglobulin G as an Urgent Treatment Option During Emerging Virus Outbreaks.

During the pre-vaccine era of the COVID-19 pandemic convalescent plasma has once again emerged as a major potential therapeutic form of passive immunization that in specific cases still represents irreplaceable treatment option. There is a growing concern that variable concentration of neutralizing antibodies, present in convalescent plasma which originates from different donors, apparently affects its effectiveness. The drawback can be overcome through the downstream process of immunoglobulin fraction purification into a standardized product of improved safety and efficacy. All modern procedures are quite lengthy processes. They are also based on fractionation of large plasma quantities whose collection is not attainable during an epidemic. When outbreaks of infectious diseases are occurring more frequently, there is a great need for a more sustainable production approach that would be goal-oriented towards assuring easily and readily available immunoglobulin of therapeutic relevance. We propose a refinement strategy for the IgG preparation achieved through simplification and reduction of the processing steps. It was designed as a small but scalable process to offer an immediately available treatment option that would simultaneously be harmonized with an increased availability of convalescent plasma over the viral outbreak time-course. Concerning the ongoing pandemic status of the COVID-19, the proof of concept was demonstrated on anti-SARS-CoV-2 convalescent plasma but is likely applicable to any other type depending on the current needs. It was guided by the idea of persistent keeping of IgG molecules in the solution, so that protection of their native structure could be assured. Our manufacturing procedure provided a high-quality IgG product of above the average recovery whose composition profile was analyzed by mass spectrometry as quality control check. It was proved free from IgA and IgM as mediators of adverse transfusion reactions, as well as of any other residual impurities, since only IgG fragments were identified. The proportion of S protein-specific IgGs remained unchanged relative to the convalescent plasma. Undisturbed IgG subclass composition was accomplished as well. However, the fractionation principle affected the final product's capacity to neutralize wild-type SARS-CoV-2 infectivity, reducing it by half. Decrease in neutralization potency significantly correlated with the amount of IgM in the starting material.

Ultrapotent and broad neutralization of SARS-CoV-2 variants by modular, tetravalent, bi-paratopic antibodies.

Neutralizing antibodies (nAbs) that target the SARS-CoV-2 spike protein have received emergency use approval for treatment of COVID-19. However, with the emergence of variants of concern, there is a need for new treatment options. We report a format that enables modular assembly of bi-paratopic tetravalent nAbs with antigen-binding sites from two distinct nAbs. The tetravalent nAb purifies in high yield and exhibits biophysical characteristics that are comparable to those of clinically used therapeutic antibodies. The tetravalent nAb binds to the spike protein trimer at least 100-fold more tightly than bivalent IgGs (apparent KD < 1 pM) and neutralizes a broad array of SARS-CoV-2 pseudoviruses, chimeric viruses, and authentic viral variants with high potency. Together, these results establish the tetravalent diabody-Fc-Fab as a robust, modular platform for rapid production of drug-grade nAbs with potencies and breadth of coverage that greatly exceed those of conventional bivalent IgGs.

Recent advances in passive immunotherapies for COVID-19: The Evidence-Based approaches and clinical trials.

In late 2019, severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) emerged, causing a global pandemic called COVID-19. Currently, there is no definitive treatment for this emerging disease. Global efforts resulted in developing multiple platforms of COVID-19 vaccines, but their efficacy in humans should be wholly investigated in the long-term clinical and epidemiological follow-ups. Despite the international efforts, COVID-19 vaccination accompanies challenges, including financial and political obstacles, serious adverse effects (AEs), the impossibility of using vaccines in certain groups of people in the community, and viral evasion due to emerging novel variants of SARS-CoV-2 in many countries. For these reasons, passive immunotherapy has been considered a complementary remedy and a promising way to manage COVID-19. These approaches arebased on reduced inflammation due to inhibiting cytokine storm phenomena, immunomodulation,preventing acute respiratory distress syndrome (ARDS), viral neutralization, anddecreased viral load. This article highlights passive immunotherapy and immunomodulation approaches in managing and treating COVID-19 patients and discusses relevant clinical trials (CTs).

Potent Anti-SARS-CoV-2 Efficacy of COVID-19 Hyperimmune Globulin from Vaccine-Immunized Plasma.

Coronavirus disease 2019 (COVID-19) remains a global public health threat. Hence, more effective and specific antivirals are urgently needed. Here, COVID-19 hyperimmune globulin (COVID-HIG), a passive immunotherapy, is prepared from the plasma of healthy donors vaccinated with BBIBP-CorV (Sinopharm COVID-19 vaccine). COVID-HIG shows high-affinity binding to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) spike (S) protein, the receptor-binding domain (RBD), the N-terminal domain of the S protein, and the nucleocapsid protein; and blocks RBD binding to human angiotensin-converting enzyme 2 (hACE2). Pseudotyped and authentic virus-based assays show that COVID-HIG displays broad-spectrum neutralization effects on a wide variety of SARS-CoV-2 variants, including D614G, Alpha (B.1.1.7), Beta (B.1.351), Gamma (P.1), Kappa (B.1.617.1), Delta (B.1.617.2), and Omicron (B.1.1.529) in vitro. However, a significant reduction in the neutralization titer is detected against Beta, Delta, and Omicron variants. Additionally, assessments of the prophylactic and treatment efficacy of COVID-HIG in an Adv5-hACE2-transduced IFNAR-/- mouse model of SARS-CoV-2 infection show significantly reduced weight loss, lung viral loads, and lung pathological injury. Moreover, COVID-HIG exhibits neutralization potency similar to that of anti-SARS-CoV-2 hyperimmune globulin from pooled convalescent plasma. Overall, the results demonstrate the potential of COVID-HIG against SARS-CoV-2 infection and provide reference for subsequent clinical trials.

Equine immunoglobulin fragment F(ab')2 displays high neutralizing capability against multiple SARS-CoV-2 variants.

Neutralizing antibody-based passive immunotherapy could be an important therapeutic option against COVID-19. Herein, we demonstrate that equines hyper-immunized with chemically inactivated SARS-CoV-2 elicited high antibody titers with a strong virus-neutralizing potential, and F(ab')2 fragments purified from them displayed strong neutralization potential against five different SARS-CoV-2 variants. F(ab')2 fragments purified from the plasma of hyperimmunized horses showed high antigen-specific affinity. Experiments in rabbits suggested that the F(ab')2 displays a linear pharmacokinetics with approximate plasma half-life of 47 h. In vitro microneutralization assays using the purified F(ab')2 displayed high neutralization titers against five different variants of SARS-CoV-2 including the Delta variant, demonstrating its potential efficacy against the emerging viral variants. In conclusion, this study demonstrates that F(ab')2 generated against SARS-CoV-2 in equines have high neutralization titers and have broad target-range against the evolving variants, making passive immunotherapy a potential regimen against the existing and evolving SARS-CoV-2 variants in combating COVID-19.

RBD-SPECIFIC POLYCLONAL F(ab)2 FRAGMENTS of EQUINE ANTIBODIES in PATIENTS with MODERATE to SEVERE COVID-19 DISEASE

SARS-CoV-2, the causative agent of COVID-19, is currently generating a global pandemic. So far, dexamethasone and remdesivir have shown efficacy in adequately powered clinical trials. In addition, passive immunotherapy appears as a promising therapeutic approach, particularly for early stages of the disease in which patients have not yet established their specific immune response. Different anti-receptor binding domain (RBD) human monoclonal antibodies (mAbs) have been evaluated in the treatment of COVID-19. It has been previously shown that the RBD from the viral spike glycoprotein elicits high titers of NAbs against SARS-CoV-2 when used as immunogen in horses. In this regard, equine polyclonal antibodies (EpAbs) can represent a practical and efficient source of NAbs. EpAbs are composed of F(ab)'2 fragments generated by pepsin digestion. These fragments retain the bivalent binding capacity of IgG immunoglobulins but lack the constant region (Fc), responsible for serum sickness reactions and Fc-triggered side effects. EpAbs recognize a vast array of epitopes (limiting the risk of viral escape mutations) and tend to develop greater avidity than mAbs for their cognate antigens. In addition, EpAbs are relatively easy to manufacture allowing a fast development and scaling up for a treatment. We have previously described the development and in vitro characterization of a therapeutic based on purified equine anti-RBD F(ab)2 fragments, called INM005. INM005 shows a very high serum neutralization titer against SARS-CoV-2. We conducted a phase 2/3 clinical to test the therapeutic effect of INM005 on COVID-19 patients. Albeit not having reached the primary endpoint, we found clinical improvement of hospitalized patients with SARS-CoV-2 pneumonia, particularly those with severe disease. Rate of improvement in at least two categories was statistically significantly higher for INM005 at days 14 and 21 of follow-up. Time to improvement in two ordinal categories or hospital discharge was 14·2 (± 0·7) days in the INM005 group and 16·3 (± 0·7) days in the placebo group. Subgroup analyses showed a beneficial effect of INM005 over severe patients and in those with negative baseline antibodies. Overall mortality was 6·9% the INM005 group and 11·4% in the placebo group. Adverse events of special interest were mild or moderate;no anaphylaxis was reported. Based on these results, ANMAT granted the emergency use approval of INM005 to treat hospitalized COVID-19 severe patients. Following approval, more than 20,000 patients have been treated with INM005. We will be presenting the results of the "real world use of this immunotherapy during the second wave of the pandemics in Argentina.

In vitro Characterization of Anti-SARS-CoV-2 Intravenous Immunoglobulins (IVIg) Produced From Plasma of Donors Immunized With the BNT162b2 Vaccine and Its Comparison With a Similar Formulation Produced From Plasma of COVID-19 Convalescent Donors.

Despite vaccines are the main strategy to control the ongoing global COVID-19 pandemic, their effectiveness could not be enough for individuals with immunosuppression. In these cases, as well as in patients with moderate/severe COVID-19, passive immunization with anti-SARS-CoV-2 immunoglobulins could be a therapeutic alternative. We used caprylic acid precipitation to prepare a pilot-scale batch of anti-SARS-CoV-2 intravenous immunoglobulins (IVIg) from plasma of donors immunized with the BNT162b2 (Pfizer-BioNTech) anti-COVID-19 vaccine (VP-IVIg) and compared their in vitro efficacy and safety with those of a similar formulation produced from plasma of COVID-19 convalescent donors (CP-IVIg). Both formulations showed immunological, physicochemical, biochemical, and microbiological characteristics that meet the specifications of IVIg formulations. Moreover, the concentration of anti-RBD and ACE2-RBD neutralizing antibodies was higher in VP-IVIg than in CP-IVIg. In concordance, plaque reduction neutralization tests showed inhibitory concentrations of 0.03-0.09 g/L in VP-IVIg and of 0.06-0.13 in CP-IVIg. Thus, VP-IVIg has in vitro efficacy and safety profiles that justify their evaluation as therapeutic alternative for clinical cases of COVID-19. Precipitation with caprylic acid could be a simple, feasible, and affordable alternative to produce formulations of anti-SARS-CoV-2 IVIg to be used therapeutically or prophylactically to confront the COVID-19 pandemic in middle and low-income countries.

Anti-SARS-CoV-2 and anti-cytokine storm neutralizing antibody therapies against COVID-19: Update, challenges, and perspectives.

Coronavirus disease 2019 (COVID-19) has been declared by the World Health Organization (WHO) as a pandemic since March 2020. This disease is caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). The only available tools to avoid contamination and transmission of this virus are physical distancing, the use of N95 and surgical masks, and hand hygiene. Vaccines are another essential tool to reduce the impact of the pandemic, though these present challenges in terms of production and logistics, particularly in underdeveloped and developing countries. One of the critical early research findings is the interaction of the spike virus protein with the angiotensin-converting enzyme 2 (ACE2) human receptor. Developing strategies to block this interaction has therefore been identified as a way to treat this infection. Neutralizing antibodies (nAbs) have emerged as a therapeutic approach since the pandemic started. Infected patients may be asymptomatic or present with mild symptoms, and others may evolve to moderate or severe disease, leading to death. An immunological phenomenon known as cytokine storm has been observed in patients with severe disease characterized by a proinflammatory cytokine cascade response that leads to lung injury. Thus, some treatment strategies focus on anti-cytokine storm nAbs. This review summarizes the latest advances in research and clinical trials, challenges, and perspectives on antibody-based treatments (ABT) as therapies against COVID-19.

Use of Monoclonal Antibody to Treat COVID-19 in Children and Adolescents: Risk of Abuse of Prescription and Exacerbation of Health Inequalities.

Monoclonal antibodies (mAbs) that neutralize SARS-CoV-2 in infected patients are a new class of antiviral agents approved as a type of passive immunotherapy. They should be administered to adults and children (≥12 years old, weighing ≥ 40 kg) with SARS-CoV-2 positivity, and who are suffering from a chronic underlying disease and are at risk of severe COVID-19 and/or hospitalization. The aim of this manuscript is to discuss the benefit-to-risk of mAb therapy to treat COVID-19 in pediatric age, according to current reports. A problem is that the authorization for mAbs use in children was given without studies previously evaluating the efficacy, safety and tolerability of mAbs in pediatric patients. Moreover, although the total number of children with chronic severe underlying disease is not marginal, the risk of severe COVID-19 in pediatric age is significantly reduced than in adults and the role of chronic underlying disease as a risk factor of severe COVID-19 development in pediatric patients is far from being precisely defined. In addition, criteria presently suggested for use of mAbs in children and adolescents are very broad and may cause individual clinicians or institutions to recommend these agents on a case-by-case basis, with an abuse in mAbs prescriptions and an exacerbation of health inequalities while resources are scarce. Several questions need to be addressed before their routine use in clinical practice, including what is their associated benefit-to-risk ratio in children and adolescents, who are the patients that could really have benefit from their use, and if there is any interference of mAb therapy on recommended vaccines. While we wait for answers to these questions from well-conducted research, an effective and safe COVID-19 vaccine for vulnerable pediatric patients remains the best strategy to prevent COVID-19 and represents the priority for public health policies.

Polyclonal hyper immunoglobulin: A proven treatment and prophylaxis platform for passive immunization to address existing and emerging diseases.

Passive immunization with polyclonal hyper immunoglobulin (HIG) therapy represents a proven strategy by transferring immunoglobulins to patients to confer immediate protection against a range of pathogens including infectious agents and toxins. Distinct from active immunization, the protection is passive and the immunoglobulins will clear from the system; therefore, administration of an effective dose must be maintained for prophylaxis or treatment until a natural adaptive immune response is mounted or the pathogen/agent is cleared. The current review provides an overview of this technology, key considerations to address different pathogens, and suggested improvements. The review will reflect on key learnings from development of HIGs in the response to public health threats due to Zika, influenza, and severe acute respiratory syndrome coronavirus 2.

Convalescent plasma for the treatment of patients with severe coronavirus disease 2019: A preliminary report.

BACKGROUND: The role of convalescent plasma therapy for patients with coronavirus disease 2019 (COVID-19) is unclear. METHODS: We retrospectively compared outcomes in a cohort of critical COVID-19 patients who received standard care (SC Group) and those who, in addition, received convalescent plasma (CP Group). RESULTS: In total, 40 patients were included in each group. The median patient age was 53.5 years (interquartile range [IQR] 42-60.5), and the majority of patients required invasive ventilation (69, 86.2%). Plasma was harvested from donors after a median of 37 days (IQR 31-46) from the first positive severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) polymerase chain reaction (PCR) result and 26 days (IQR 21-32) after documented viral clearance; it was administered after a median of 10 days (IQR 9-10) from the onset of symptoms and 2.5 days (IQR 2-4) from admission to intensive care unit. The primary endpoint of improvement in respiratory support status within 28 days was achieved in 26 patients (65%) in the SC Group and 31 patients (77.5%) in the CP Group (p = .32). The 28-day all-cause mortality (12.5% vs. 2.5%; p = .22) and viral clearance (65% vs. 55%; p = .49) were not significantly different between the two groups. Convalescent plasma was not significantly associated with the primary endpoint (adjusted hazard ratio 0.87; 95% confidence interval 0.51-1.49; p = .62). Adverse events were balanced between the two study groups. CONCLUSION: In severe COVID-19, convalescent plasma therapy was not associated with clinical benefits. Randomized trials are required to confirm our findings.

The Road towards Polyclonal Anti-SARS-CoV-2 Immunoglobulins (Hyperimmune Serum) for Passive Immunization in COVID-19.

Effective treatments specific for COVID-19 are still lacking. In the setting of passive immunotherapies based on neutralizing antibodies (nAbs), randomized controlled trials of COVID-19 convalescent plasma (CCP) anti-SARS-CoV-2 Spike protein monoclonal antibodies (mAb), which have been granted emergency use authorization, have suggested benefit in early disease course (less than 72 hours from symptoms and seronegative). Meanwhile, polyclonal immunoglobulins (i.e., hyperimmune serum), derived either from CCP donations or from animals immunized with SARS-CoV-2 antigens, are likely to become the next nAb-derived candidate. We here discuss the pros and cons of hyperimmune serum versus CCP and mAb, and summarize the ongoing clinical trials of COVID-19 hyperimmune sera.