Neutralizing and binding activities against SARS-CoV-1/2, MERS-CoV, and human coronaviruses 229E and OC43 by normal human intravenous immunoglobulin derived from healthy donors in Japan

Successful management of persistent COVID-19 using combination antiviral therapy (nirmatrelvir/ritonavir and remdesivir) and intravenous immunoglobulin transfusion in an immunocompromised host who had received CD20 depleting therapy for follicular lymphoma

The management of persistent symptomatic coronavirus disease 2019 (COVID-19) infections in immunocompromised patients remains unclear. Here, we present the first case of successful antiviral therapy (nirmatrelvir/ritonavir and remdesivir) in combination with intravenous immunoglobulin (IVIg) in a patient who had received CD20 depleting therapy for follicular lymphoma and experienced recurrent COVID-19 relapses. After the patient received IVIg treatment, the viral load decreased without recurrence. Subsequently, it was found that the anti-spike antibody titer in the administered immunoglobulin was high at 9528.0 binding antibody units/mL. Our case highlights the potential of combination therapy with selective IVIg and antiviral drugs for relapsed immunocompromised COVID-19 patients who have received CD20 depleting therapy.

Terpenes and cannabidiol against human corona and influenza viruses-Anti-inflammatory and antiviral in vitro evaluation

The activity of the terpenes and Cannabidiol (CBD) against human coronavirus (HCoV) strain OC43 and influenza A (H1N1) was evaluated in human lung fibroblasts (MRC-5 cells). Also, we examined whether these ingredients inhibit pro-inflammatory cytokines in peripheral blood mononuclear cells (PBMC). The tested preparations exhibited both anti-inflammatory and antiviral effects. The combination of terpenes was effective against both HCoV-OC43 and influenza A (H1N1) virus. The addition of CBD improved the antiviral activity in some, but not all cases. This variation in activity may suggest an antiviral mechanism. In addition, there was a strong correlation between the quantitative results from a cell-viability assay and the cytopathic effect after 72 h, as observed under a microscope. The anti-inflammatory properties of terpenes were demonstrated using a pro-inflammatory cytokine-inhibition assay, which revealed significant cytokine inhibition and enhanced by the addition of CBD.

Immunoglobulin replacement products protect against SARS-CoV-2 infection in vivo despite poor neutralizing activity

Immunoglobulin (IG) replacement products are used routinely in patients with immune deficiency and other immune dysregulation disorders who have poor responses to vaccination and require passive immunity conferred by commercial antibody products. The binding, neutralizing, and protective activity of intravenously administered IG against SARS-CoV-2 emerging variants remains unknown. Here, we tested 198 different IG products manufactured from December 2019 to August 2022. We show that prepandemic IG had no appreciable cross-reactivity or neutralizing activity against SARS-CoV-2. Anti-spike antibody titers and neutralizing activity against SARS-CoV-2 WA1/2020 D614G increased gradually after the pandemic started and reached levels comparable to vaccinated healthy donors 18 months after the diagnosis of the first COVID-19 case in the United States in January 2020. The average time between production to infusion of IG products was 8 months, which resulted in poor neutralization of the variant strain circulating at the time of infusion. Despite limited neutralizing activity, IG prophylaxis with clinically relevant dosing protected susceptible K18-hACE2-transgenic mice against clinical disease, lung infection, and lung inflammation caused by the XBB.1.5 Omicron variant. Moreover, following IG prophylaxis, levels of XBB.1.5 infection in the lung were higher in FcγR-KO mice than in WT mice. Thus, IG replacement products with poor neutralizing activity against evolving SARS-CoV-2 variants likely confer protection to patients with immune deficiency disorders through Fc effector function mechanisms.

Changes in Anti-SARS-CoV-2 Antibody Titers of Pooled Plasma Derived From Donors in Japan: A Potential Tool for Mass-Immunity Evaluation

The anti-spike (S), anti-nucleocapsid (N), and neutralizing activities of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) of pooled plasma derived from donors in Japan from January 2021 to April 2022 were evaluated. Anti-S titers and neutralizing activities showed a wave-like trend affected by daily vaccinations and/or the number of reported cases of SARS-CoV-2 infections, whereas anti-N titers remained at negative levels. These results suggest that anti-S and neutralizing titers would fluctuate in pooled plasma in the future. Pooled plasma may be potentially used for mass-immunity evaluation, and titer estimation in intravenous immunoglobulin, a derivative of pooled plasma.

Functional CVIDs phenotype clusters identified by the integration of immune parameters after BNT162b2 boosters

Introduction

Assessing the response to vaccinations is one of the diagnostic criteria for Common Variable Immune Deficiencies (CVIDs). Vaccination against SARS-CoV-2 offered the unique opportunity to analyze the immune response to a novel antigen. We identify four CVIDs phenotype clusters by the integration of immune parameters after BTN162b2 boosters.

Methods

We performed a longitudinal study on 47 CVIDs patients who received the 3rd and 4th vaccine dose of the BNT162b2 vaccine measuring the generation of immunological memory. We analyzed specific and neutralizing antibodies, spike-specific memory B cells, and functional T cells.

Results

We found that, depending on the readout of vaccine efficacy, the frequency of responders changes. Although 63.8% of the patients have specific antibodies in the serum, only 30% have high-affinity specific memory B cells and generate recall responses.

Discussion

Thanks to the integration of our data, we identified four functional groups of CVIDs patients with different B cell phenotypes, T cell functions, and clinical diseases. The presence of antibodies alone is not sufficient to demonstrate the establishment of immune memory and the measurement of the in-vivo response to vaccination distinguishes patients with different immunological defects and clinical diseases.

Intravenous Immunoglobulin G (IVIG) Need Assessment Survey Toward Local Manufacturing of IVIG Using a Mini-Pool Plasma Fractionation Technique

Immunoglobulin therapy has a crucial role in the treatment of primary and secondary immunodeficiencies as well as in a multitude of neurologic, hematologic, infectious, and autoimmune conditions. In the current study, a preliminary pilot scale needs assessment survey was conducted to examine the need for IVIG among patients in Addis Ababa, Ethiopia, and in so doing justify local manufacturing of IVIG products. The survey was performed by administering a structured questionnaire to private and government hospitals, a national blood bank, a regulatory body, and healthcare researchers working in academia and pharmaceutical companies. The questionnaire encompassed demographics and specific IVIG-related questions designed for each institution. Responses supplied in the study provide qualitative data. Our findings indicated that IVIG has been registered by the regulatory body for use in Ethiopia and there is a demand for the product in the country. The study also highlights that patients go as far as to clandestine markets to procure IVIG products at a cheaper price. To impede such illegal routes and make the product readily accessible, a small-scale and low-cost approach such as a mini-pool plasma fractionation technique could be implemented to locally purify and prepare IVIG using plasma collected through the national blood donation program.

Risk Factors of Severe COVID-19: A Review of Host, Viral and Environmental Factors

The clinical course and outcome of COVID-19 are highly variable, ranging from asymptomatic infections to severe disease and death. Understanding the risk factors of severe COVID-19 is relevant both in the clinical setting and at the epidemiological level. Here, we provide an overview of host, viral and environmental factors that have been shown or (in some cases) hypothesized to be associated with severe clinical outcomes. The factors considered in detail include the age and frailty, genetic polymorphisms, biological sex (and pregnancy), co- and superinfections, non-communicable comorbidities, immunological history, microbiota, and lifestyle of the patient; viral genetic variation and infecting dose; socioeconomic factors; and air pollution. For each category, we compile (sometimes conflicting) evidence for the association of the factor with COVID-19 outcomes (including the strength of the effect) and outline possible action mechanisms. We also discuss the complex interactions between the various risk factors.

Antibody response after COVID-19 vaccination in intravenous immunoglobulin-treated immune neuropathies

BACKGROUND AND PURPOSE

This study assessed the prevalence of anti-SARS-CoV-2 antibodies in therapeutic immunoglobulin and their impact on serological response to COVID-19 mRNA vaccine in patients with intravenous immunoglobulin (IVIg)-treated chronic immune neuropathies.

METHODS

Forty-six samples of different brands or lots of IVIg or subcutaneous IgG were analyzed for anti-SARS-CoV-2 IgG using enzyme-linked immunosorbent assay and chemiluminescent microparticle immunoassay. Blood sera from 16 patients with immune neuropathies were prospectively analyzed for anti-SARS-CoV-2 IgA, IgG, and IgM before and 1 week after IVIg infusion subsequent to consecutive COVID-19 mRNA vaccine doses and after 12 weeks. These were compared to 42 healthy subjects.

RESULTS

Twenty-four (52%) therapeutic immunoglobulin samples contained anti-SARS-CoV-2 IgG. All patients with immune neuropathies (mean age = 65 ± 16 years, 25% female) were positive for anti-SARS-CoV-2 IgG after COVID-19 vaccination. Anti-SARS-CoV-2 IgA titers significantly decreased 12-14 weeks after vaccination (p = 0.02), whereas IgG titers remained stable (p = 0.2). IVIg did not significantly reduce intraindividual anti-SARS-CoV-2 IgA/IgG serum titers in immune neuropathies (p = 0.69). IVIg-derived anti-SARS-CoV-2 IgG did not alter serum anti-SARS-CoV-2 IgG decrease after IVIg administration (p = 0.67).

CONCLUSIONS

Our study indicates that IVIg does not impair the antibody response to COVID-19 mRNA vaccine in a short-term observation, when administered a minimum of 2 weeks after each vaccine dose. The infusion of current IVIg preparations that contain anti-SARS-CoV-2 IgG does not significantly alter serum anti-SARS-CoV-2 IgG titers.

Preclinical study of a DNA vaccine targeting SARS-CoV-2

To fight against the worldwide COVID-19 pandemic, the development of an effective and safe vaccine against SARS-CoV-2 is required. As potential pandemic vaccines, DNA/RNA vaccines, viral vector vaccines and protein-based vaccines have been rapidly developed to prevent pandemic spread worldwide. In this study, we designed plasmid DNA vaccine targeting the SARS-CoV-2 Spike glycoprotein (S protein) as pandemic vaccine, and the humoral, cellular, and functional immune responses were characterized to support proceeding to initial human clinical trials. After intramuscular injection of DNA vaccine encoding S protein with alum adjuvant (three times at 2-week intervals), the humoral immunoreaction, as assessed by anti-S protein or anti-receptor-binding domain (RBD) antibody titers, and the cellular immunoreaction, as assessed by antigen-induced IFNγ expression, were up-regulated. In IgG subclass analysis, IgG2b was induced as the main subclass. Based on these analyses, DNA vaccine with alum adjuvant preferentially induced Th1-type T cell polarization. We confirmed the neutralizing action of DNA vaccine-induced antibodies by a binding assay of RBD recombinant protein with angiotensin-converting enzyme 2 (ACE2), a receptor of SARS-CoV-2, and neutralization assays using pseudo-virus, and live SARS-CoV-2. Further B cell epitope mapping analysis using a peptide array showed that most vaccine-induced antibodies recognized the S2 and RBD subunits. Finally, DNA vaccine protected hamsters from SARS-CoV-2 infection. In conclusion, DNA vaccine targeting the spike glycoprotein of SARS-CoV-2 might be an effective and safe approach to combat the COVID-19 pandemic.

Function matters: Coronavirus cross-binding antibodies do not cross-neutralize

Background

During the current pandemic, the severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) neutralization capacity of the immunoglobulin (IG) supply has changed from undetectable for lots manufactured from plasma collected before the pandemic, to now highly potent.

Objective

As antibodies induced by exposure to or vaccination against coronaviruses were shown to be cross-coronavirus reactive, it was of interest to understand whether SARS-CoV-2 neutralizing antibodies would result in increased functional IG potency also against seasonal coronaviruses.

Methods

IG lots from US plasma collected before SARS-CoV-2 emerged and collected during the pandemic were analyzed by live virus neutralization assay for SARS-CoV-2 and seasonal human coronaviruses (HCoVs) NL63 and OC43 neutralizing antibody content.

Results

Pre-pandemic IG showed no SARS-CoV-2 neutralizing antibody titers. However, IG lots produced from plasma of post-coronavirus disease 2019 (COVID-19) individuals exhibited robust anti-SARS-CoV-2 potency (1,267 IU/ml) which further increased ~4-fold in pandemic IG lots reaching a mean titer of 5,122 IU/ml. Nonetheless, neutralizing antibody potencies to the HCoVs NL63 and OC43 remained stable over this period, i.e., have not increased correspondingly.

Conclusion

The present results show that cross-coronavirus-reactive antibodies are not cross-neutralizing, i.e., SARS-CoV-2 antibodies do not neutralize seasonal coronaviruses NL63 and OC43.

Elevated CD21low B Cell Frequency Is a Marker of Poor Immunity to Pfizer-BioNTech BNT162b2 mRNA Vaccine Against SARS-CoV-2 in Patients with Common Variable Immunodeficiency

PURPOSE

Limited data is available on the effect of COVID-19 vaccination in immunocompromised individuals. Here, we provide the results from vaccinating a single-center cohort of patients with common variable immunodeficiency (CVID).

METHODS

In a prospective, open-label clinical trial, 50 patients with CVID and 90 age-matched healthy controls (HC) were analyzed for SARS-CoV-2 spike antibody (Ab) production after one or two doses of the Pfizer-BioNTech BNT162b2 mRNA vaccine. Additionally, in selected patients, SARS-CoV-2 spike-specific T-cells were assessed.

RESULTS

A potent vaccine-induced anti-spike-specific IgG Ab response was observed in all the HC. In contrast, only 68.3% of the CVID patients seroconverted, with median titers of specific Ab being 83-fold lower than in HC. In fact, only 4/46 patients (8.6%) of patients who were seronegative at baseline reached the threshold for an optimal response (250 U/mL). Using the EUROclass definition, patients with either a reduced proportion, but not absolute counts, of switched memory B-cells or having an increased frequency of CD21low B-cells generally generated poor vaccine responses. Overall, CVID-patients had reduced spike-specific IFN-γ positive CD4+ T cell responses 2 weeks after the second dose, compared to HC. The total CD4 and CD4 central memory cell counts correlated with humoral immunity to the vaccine.

CONCLUSIONS

CVID patients with low frequency of switched memory B-cells or an increased frequency of CD21low B-cells according to the EUROclass definition demonstrated poor responses to Pfizer-BioNTech BNT162b2 mRNA vaccination. Cellular immune responses were significantly affected, affirming that the defect in CVID is not limited to humoral immunity.

Potential therapeutic approach of intravenous immunoglobulin against COVID-19

Since the outbreak of the novel coronavirus disease (COVID-19), the therapeutic and management options to reduce the burden of the COVID-19 disease are under investigation. IVIG therapy is used as an effective treatment for immunodeficient patients and patients with inflammatory or autoimmune conditions. The therapeutic effect of IVIG in COVID-19 patients has been investigated. But, the results are controversial and some studies reported no benefit of IVIG therapy. More clinical trials on the effect of IVIG therapy in COVID-19 patients should be performed to establish a certain conclusion about IVIG effectiveness.

Heterologous humoral immunity to human and zoonotic coronaviruses: Aiming for the achilles heel

Coronaviruses are evolutionarily successful RNA viruses, common to multiple avian, amphibian and mammalian hosts. Despite their ubiquity and potential impact, knowledge of host immunity to coronaviruses remains incomplete, partly owing to the lack of overt pathogenicity of endemic human coronaviruses (HCoVs), which typically cause common colds. However, the need for deeper understanding became pressing with the zoonotic introduction of three novel coronaviruses in the past two decades, causing severe acute respiratory syndromes in humans, and the unfolding pandemic of coronavirus disease 2019 (COVID-19), caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). This renewed interest not only triggered the discovery of two of the four HCoVs, but also uncovered substantial cellular and humoral cross-reactivity with shared or related coronaviral antigens. Here, we review the evidence for cross-reactive B cell memory elicited by HCoVs and its potential impact on the puzzlingly variable outcome of SARS-CoV-2 infection. The available data indicate targeting of highly conserved regions primarily in the S2 subunits of the spike glycoproteins of HCoVs and SARS-CoV-2 by cross-reactive B cells and antibodies. Rare monoclonal antibodies reactive with conserved S2 epitopes and with potent virus neutralising activity have been cloned, underscoring the potential functional relevance of cross-reactivity. We discuss B cell and antibody cross-reactivity in the broader context of heterologous humoral immunity to coronaviruses, as well as the limits of protective immune memory against homologous re-infection. Given the bidirectional nature of cross-reactivity, the unprecedented current vaccination campaign against SARS-CoV-2 is expected to impact HCoVs, as well as future zoonotic coronaviruses attempting to cross the species barrier. However, emerging SARS-CoV-2 variants with resistance to neutralisation by vaccine-induced antibodies highlight a need for targeting more constrained, less mutable parts of the spike. The delineation of such cross-reactive areas, which humoral immunity can be trained to attack, may offer the key to permanently shifting the balance of our interaction with current and future coronaviruses in our favour.

Most Japanese individuals are genetically predisposed to recognize an immunogenic protein fragment shared between COVID-19 and common cold coronaviruses

In the spring of 2020, we and others hypothesized that T cells in COVID-19 patients may recognize identical protein fragments shared between the coronaviruses of the common cold and COVID-19 and thereby confer cross-virus immune memory. Here, we look at this issue by screening studies that, since that time, have experimentally addressed COVID-19 associated T cell specificities. Currently, the identical T cell epitope shared between COVID-19 and common cold coronaviruses most convincingly identified as immunogenic is the CD8 + T cell epitope VYIGDPAQL if presented by the MHC class I allele HLA-A*24:02. The HLA-A*24:02 allele is found in the majority of Japanese individuals and several indigenous populations in Asia, Oceania, and the Americas. In combination with histories of common cold infections, HLA-A*24:02 may affect their protection from COVID-19.

Successful Treatment of Elderly Male With COVID-19 Infection With Severe Acute Respiratory Distress Syndrome Using Multimodal Therapy, Including Immune Modulation Therapy

A 78-year-old man fell from a ladder and suffered a right distal tibial fracture. On the seventh day after injury, he developed a low-grade fever and was isolated in a private room. Polymerase chain reaction for COVID-19 was positive (day 4 from the day of saliva sampling). On day 5, he required 1 liter per minute of oxygen and dexamethasone therapy was initiated. On day 6, his D-dimer level was 25.0 μg/mL, and continuous infusion of heparin was initiated. From day 7, he was administered remdesivir. On day 9, his oxygenation suddenly showed a remarkable deterioration. He received a tentative diagnosis of COVID-19-induced pneumonia accompanied by severe acute respiratory distress syndrome (ARDS) and underwent urgent tracheal intubation and mechanical ventilation. He also received intravenous immunoglobulin (IVIG) and was also administered glycyrrhizin. His oxygenation gradually improved and extubation was performed on day 15. Following rehabilitation, he did not require oxygen on day 19. On day 20, his D-dimer level was found to be increased and enhanced computed tomography revealed pulmonary embolism. He was prescribed a direct oral anticoagulant. On day 28 he was transferred to a general ward for rehabilitation. These unspecific antiviral therapies and immune modulation therapy may be useful treatments for the main cause of ARDS, which may explain the favorable outcome that was obtained in the present case.