33,976 results match your criteria antibody neutralization

Impact of convalescent plasma therapy on SARS CoV-2 antibody profile in COVID-19 patients.

Clin Infect Dis 2021 Apr 16. Epub 2021 Apr 16.

Division of Viral Products, Center for Biologics Evaluation and Research (CBER), FDA, Silver Spring, Maryland, USA.

Convalescent plasma (CP) have been used for treatment of COVID-19, but their effectiveness varies significantly. Moreover, the impact of CP treatment on the composition of SARS-CoV-2 antibodies in COVID-19 patients and antibody markers that differentiate between those who survive and those who succumb to the COVID-19 disease are not well understood. Herein, we performed longitudinal analysis of antibody profile on 115 sequential plasma samples from 16 hospitalized COVID-19 patients treated with either CP or standard of care, only half of them survived. Read More

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SARS-CoV-2 mutations acquired in mink reduce antibody-mediated neutralization.

Cell Rep 2021 Apr 3:109017. Epub 2021 Apr 3.

Infection Biology Unit, German Primate Center - Leibniz Institute for Primate Research, Kellnerweg 4, 37077 Göttingen, Germany; Faculty of Biology and Psychology, University Göttingen, Wilhelmsplatz 1, 37073 Göttingen, Germany. Electronic address:

Transmission of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) from humans to farmed mink has been observed in Europe and the US. In the infected animals, viral variants arose that harbored mutations in the spike (S) protein, the target of neutralizing antibodies, and these variants were transmitted back to humans. This raised concerns that mink might become a constant source of human infection with SARS-CoV-2 variants associated with an increased threat to human health and resulted in mass culling of mink. Read More

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Analytical and clinical performances of a SARS-CoV-2 S-RBD IgG assay: comparison with neutralization titers.

Clin Chem Lab Med 2021 Apr 13. Epub 2021 Apr 13.

Department of Medicine-DIMED, Medical School, University of Padova, Padova, Italy.

Objectives: SARS-CoV-2 serology presents an important role in several aspects of COVID-19 pandemic. Immunoassays performances have to be accurately evaluated and correlated with neutralizing antibodies. We investigated the analytical and clinical performances of a SARS-CoV-2 RBD IgG assay, automated on a high throughput platform, and the correlation of the antibodies (Ab) levels with the plaque reduction neutralization (PRNT) Ab titers. Read More

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Enhancement of antibody-dependent cellular cytotoxicity and phagocytosis in anti-HIV-1 bovine chimeric broadly-neutralizing antibodies.

J Virol 2021 Apr 14. Epub 2021 Apr 14.

Department of Microbiology and Immunology, Peter Doherty Institute for Infection and Immunity, University of Melbourne, VIC 3000, Australia

No prophylactic vaccine has provided robust protection against HIV-1. Vaccine-induced broadly neutralizing antibodies (bnAbs) have not been achieved in humans and most animals, however cows vaccinated with HIV-1 envelope trimers produce bnAbs with unusually long third heavy complementarity determining regions (CDRH3). Alongside neutralization, Fc-mediated effector functions including antibody-dependent cellular cytotoxicity (ADCC) and phagocytosis (ADP) may be critical for in bnAb antiviral activity. Read More

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Imbalance between T helper 1 and regulatory T cells plays a detrimental role in experimental Parkinson's disease in mice.

J Int Med Res 2021 Apr;49(4):300060521998471

Department of Geriatrics, Ningbo First Hospital, Ningbo, China.

Objective: Parkinson's disease (PD) is a degenerative disorder characterized by steady motor function loss. PD pathogenesis remains inconclusive, but aberrant immune responses might play important roles. We hypothesized that imbalance between T helper (Th) 1 and regulatory T (Treg) cells was essential in experimental PD. Read More

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Convergence of a common solution for broad ebolavirus neutralization by glycan cap-directed human antibodies.

Cell Rep 2021 Apr;35(2):108984

Department of Integrative Structural and Computational Biology, The Scripps Research Institute, La Jolla, CA 92037, USA. Electronic address:

Antibodies that target the glycan cap epitope on the ebolavirus glycoprotein (GP) are common in the adaptive response of survivors. A subset is known to be broadly neutralizing, but the details of their epitopes and basis for neutralization are not well understood. Here, we present cryoelectron microscopy (cryo-EM) structures of diverse glycan cap antibodies that variably synergize with GP base-binding antibodies. Read More

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Effects of SARS-CoV-2 variants on vaccine efficacy and response strategies.

Expert Rev Vaccines 2021 Apr 14:1-9. Epub 2021 Apr 14.

Institute of Biological Products, Division of Hepatitis and Enterovirus Vaccines, National Institutes for Food and Drug Control, Beijing, China.

Introduction: As the global severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) pandemic continues to spread, several variants have emerged. Variants B.1. Read More

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Sera neutralizing activities against SARS-CoV-2 and multiple variants six month after hospitalization for COVID-19.

Clin Infect Dis 2021 Apr 14. Epub 2021 Apr 14.

Université de Paris, INSERM, PARCC, F-75006 Paris, France.

Background: Humoral response to SARS-CoV-2 occurs within the first weeks after COVID-19. Those antibodies exert a neutralizing activity against SARS-CoV-2, whose evolution overtime after COVID-19 as well as efficiency against novel variants are however poorly characterized.

Methods: In this prospective study, sera of 107 patients hospitalized with COVID-19 were collected at 3- and 6-months post-infection. Read More

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Neutralization of SARS-CoV-2 variants by convalescent and vaccinated serum.

medRxiv 2021 Apr 9. Epub 2021 Apr 9.

We tested human sera from large, demographically balanced cohorts of BNT162b2 vaccine recipients (n=51) and COVID-19 patients (n=44) for neutralizing antibodies against SARS-CoV-2 variants B.1.1. Read More

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Glucocorticoids and B Cell Depleting Agents Substantially Impair Immunogenicity of mRNA Vaccines to SARS-CoV-2.

medRxiv 2021 Apr 9. Epub 2021 Apr 9.

Background: Individuals with chronic inflammatory diseases (CID) are frequently treated with immunosuppressive medications that can increase their risk of severe COVID-19. While novel mRNA-based SARS-CoV-2 vaccination platforms provide robust protection in immunocompetent individuals, the immunogenicity in CID patients on immunosuppression is not well established. Therefore, determining the effectiveness of SARS-CoV-2 vaccines in the setting of immunosuppression is essential to risk-stratify CID patients with impaired protection and provide clinical guidance regarding medication management. Read More

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Structural basis for broad sarbecovirus neutralization by a human monoclonal antibody.

bioRxiv 2021 Apr 8. Epub 2021 Apr 8.

The recent emergence of SARS-CoV-2 variants of concern (VOC) and the recurrent spillovers of coronaviruses in the human population highlight the need for broadly neutralizing antibodies that are not affected by the ongoing antigenic drift and that can prevent or treat future zoonotic infections. Here, we describe a human monoclonal antibody (mAb), designated S2×259, recognizing a highly conserved cryptic receptor-binding domain (RBD) epitope and cross-reacting with spikes from all sarbecovirus clades. S2×259 broadly neutralizes spike-mediated entry of SARS-CoV-2 including the B. Read More

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Efficacy and breadth of adjuvanted SARS-CoV-2 receptor-binding domain nanoparticle vaccine in macaques.

bioRxiv 2021 Apr 10. Epub 2021 Apr 10.

Emergence of novel variants of the severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) underscores the need for next-generation vaccines able to elicit broad and durable immunity. Here we report the evaluation of a ferritin nanoparticle vaccine displaying the receptor-binding domain of the SARS-CoV-2 spike protein (RFN) adjuvanted with Army Liposomal Formulation QS-21 (ALFQ). RFN vaccination of macaques using a two-dose regimen resulted in robust, predominantly Th1 CD4+ T cell responses and reciprocal peak mean neutralizing antibody titers of 14,000-21,000. Read More

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Antibodies to the SARS-CoV-2 receptor-binding domain that maximize breadth and resistance to viral escape.

bioRxiv 2021 Apr 8. Epub 2021 Apr 8.

An ideal anti-SARS-CoV-2 antibody would resist viral escape , have activity against diverse SARS-related coronaviruses , and be highly protective through viral neutralization and effector functions . Understanding how these properties relate to each other and vary across epitopes would aid development of antibody therapeutics and guide vaccine design. Here, we comprehensively characterize escape, breadth, and potency across a panel of SARS-CoV-2 antibodies targeting the receptor-binding domain (RBD), including S309 , the parental antibody of the late-stage clinical antibody VIR-7831. Read More

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Neutralizing activity of Sputnik V vaccine sera against SARS-CoV-2 variants.

Res Sq 2021 Apr 8. Epub 2021 Apr 8.

The novel pandemic betacoronavirus, severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), has infected at least 120 million people since its identification as the cause of a December 2019 viral pneumonia outbreak in Wuhan, China1,2. Despite the unprecedented pace of vaccine development, with six vaccines already in use worldwide, the emergence of SARS-CoV-2 'variants of concern' (VOC) across diverse geographic locales have prompted re-evaluation of strategies to achieve universal vaccination3. All three officially designated VOC carry Spike (S) polymorphisms thought to enable escape from neutralizing antibodies elicited during initial waves of the pandemic4-8. Read More

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Oral multivalent epitope vaccine, based on UreB, HpaA, CAT, and LTB, for prevention and treatment of Helicobacter pylori infection in C57BL / 6 mice.

Helicobacter 2021 Apr 12:e12807. Epub 2021 Apr 12.

Department of Natural Medicinal Chemistry, China Pharmaceutical University, Nanjing, China.

Background: As the resistance of Helicobacter pylori to traditional triple therapy is gradually revealed, an increasing number of people are focusing on vaccine treatments for H. pylori infection. Epitope vaccines are a promising strategy for the treatment of H. Read More

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Use of population PK/PD approach to model the thrombin generation assay: assessment in haemophilia A plasma samples spiked by a TFPI antibody.

J Pharmacokinet Pharmacodyn 2021 Apr 12. Epub 2021 Apr 12.

School of Pharmacy, University of Waterloo, Kitchener, ON, Canada.

The thrombin generation (TG) assay is a well-established tool to capture the clotting potential of any healthy or haemophiliac subject. It measures ex vivo the kinetics of thrombin activation throughout the coagulation. Clinical studies allowed to create two databases gathering the coagulation factor levels and the thrombin generation profile of 40 healthy and 40 haemophiliac A (HA) subjects. Read More

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Serological evidence of West Nile virus infection in human populations and domestic birds in the Northwest of Morocco.

Comp Immunol Microbiol Infect Dis 2021 Apr 5;76:101646. Epub 2021 Apr 5.

Institut Pasteur du Maroc, Service de Parasitologie et des Maladies Vectorielles, Place Louis Pasteur, Casablanca 20360, Morocco. Electronic address:

West Nile virus (WNV) was recently detected in Culex pipiens mosquitoes in Morocco. The aim of this study was to evaluate the seroprevalence of WNV in humans and in domestic birds in two regions of Morocco by the detection of IgG antibodies. Blood samples were obtained from 91 human patients and 92 domestic birds from September to December 2019. Read More

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Development and qualification of a fast, high-throughput and robust imaging-based neutralization assay for respiratory syncytial virus.

J Immunol Methods 2021 Apr 9:113054. Epub 2021 Apr 9.

Analytical Research & Development, MRL, Merck & Co., Inc., Kenilworth, NJ, USA.

Respiratory syncytial virus (RSV) is a common pathogen causing severe respiratory illness in infants and elder adults. The development of an effective RSV vaccine is an important unmet medical need and an area of active research. The traditional method for testing neutralizing antibodies against RSV in clinical trials is the plaque reduction neutralization test (PRNT), which uses 24-well plates and needs six days post infection to develop viral plaques. Read More

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Distinct clonal evolution of B-cells in HIV controllers with neutralizing antibody breadth.

Elife 2021 04 12;10. Epub 2021 Apr 12.

Ragon Institute of MGH, MIT and Harvard, Cambridge, United States.

A minor subset of individuals infected with HIV-1 develop antibody neutralization breadth during the natural course of the infection, often linked to chronic, high-level viremia. Despite significant efforts, vaccination strategies have been unable to induce similar neutralization breadth and the mechanisms underlying neutralizing antibody induction remain largely elusive. Broadly neutralizing antibody responses can also be found in individuals who control HIV to low and even undetectable plasma levels in the absence of antiretroviral therapy, suggesting that high antigen exposure is not a strict requirement for neutralization breadth. Read More

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Validation of a diphtheria toxoid multiplex bead assay for serosurveys.

Diagn Microbiol Infect Dis 2021 Mar 13;100(3):115371. Epub 2021 Mar 13.

Division of Foodborne, Waterborne, and Environmental Diseases, Centers for Disease Control and Prevention, Atlanta, GA, USA.

We validated a multiplex bead assay for diphtheria toxoid IgG antibodies against the Vero cell toxin neutralization test using 1300 specimens (correlation = 0.88). At the ≥0. Read More

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Clinical validation of the Siemens quantitative SARS-CoV-2 spike IgG assay (sCOVG) reveals improved sensitivity and a good correlation with virus neutralization titers.

Clin Chem Lab Med 2021 Apr 9. Epub 2021 Apr 9.

Central Institute of Clinical and Chemical Laboratory Diagnostics, University Hospital of Innsbruck, Innsbruck, Austria.

Objectives: Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infections cause coronavirus disease 2019 (COVID-19) and induce a specific antibody response. Serological assays detecting IgG against the receptor binding domain (RBD) of the spike (S) protein are useful to monitor the immune response after infection or vaccination. The objective of our study was to evaluate the clinical performance of the Siemens SARS-CoV-2 IgG (sCOVG) assay. Read More

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Capturing Cytokines with Advanced Materials: A Potential Strategy to Tackle COVID-19 Cytokine Storm.

Adv Mater 2021 Apr 10:e2100012. Epub 2021 Apr 10.

Institute of Biomedical Health Technology and Engineering, Shenzhen Bay Laboratory, Shenzhen, 518132, China.

The COVID-19 pandemic, induced by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), has caused great impact on the global economy and people's daily life. In the clinic, most patients with COVID-19 show none or mild symptoms, while approximately 20% of them develop severe pneumonia, multiple organ failure, or septic shock due to infection-induced cytokine release syndrome (the so-called "cytokine storm"). Neutralizing antibodies targeting inflammatory cytokines may potentially curb immunopathology caused by COVID-19; however, the complexity of cytokine interactions and the multiplicity of cytokine targets make attenuating the cytokine storm challenging. Read More

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Seroprevalence and correlates of SARS-CoV-2 neutralizing antibodies from a population-based study in Bonn, Germany.

Nat Commun 2021 04 9;12(1):2117. Epub 2021 Apr 9.

Population Health Sciences, German Center for Neurodegenerative Diseases (DZNE), Bonn, Germany.

To estimate the seroprevalence and temporal course of SARS-CoV-2 neutralizing antibodies, we embedded a multi-tiered seroprevalence survey within an ongoing community-based cohort study in Bonn, Germany. We first assessed anti-SARS-CoV-2 immunoglobulin G levels with an immunoassay, followed by confirmatory testing of borderline and positive test results with a recombinant spike-based immunofluorescence assay and a plaque reduction neutralization test (PRNT). Those with a borderline or positive immunoassay result were retested after 4 to 5 months. Read More

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Neutralization potency of monoclonal antibodies recognizing dominant and subdominant epitopes on SARS-CoV-2 Spike is impacted by the B.1.1.7 variant.

Immunity 2021 Apr 1. Epub 2021 Apr 1.

Department of Infectious Diseases, School of Immunology & Microbial Sciences, King's College London, London, UK; Genotype-to-Phenotype UK National Virology Consortium. Electronic address:

Interaction of the SARS-CoV-2 Spike receptor binding domain (RBD) with the receptor ACE2 on host cells is essential for viral entry. RBD is the dominant target for neutralizing antibodies, and several neutralizing epitopes on RBD have been molecularly characterized. Analysis of circulating SARS-CoV-2 variants has revealed mutations arising in the RBD, N-terminal domain (NTD) and S2 subunits of Spike. Read More

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Mutations derived from horseshoe bat ACE2 orthologs enhance ACE2-Fc neutralization of SARS-CoV-2.

PLoS Pathog 2021 Apr 9;17(4):e1009501. Epub 2021 Apr 9.

Department of Immunology and Microbiology, The Scripps Research Institute, Jupiter, FL, United States of America.

The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) spike (S) protein mediates infection of cells expressing angiotensin-converting enzyme 2 (ACE2). ACE2 is also the viral receptor of SARS-CoV (SARS-CoV-1), a related coronavirus that emerged in 2002-2003. Horseshoe bats (genus Rhinolophus) are presumed to be the original reservoir of both viruses, and a SARS-like coronavirus, RaTG13, closely related to SARS-CoV-2, has been identified in one horseshoe-bat species. Read More

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Preservation of neutralizing antibody function in COVID-19 convalescent plasma treated using a riboflavin and ultraviolet light-based pathogen reduction technology.

Vox Sang 2021 Apr 9. Epub 2021 Apr 9.

Terumo Blood and Cell Technologies, Lakewood, CO, USA.

Background And Objectives: Convalescent plasma (CP) has been embraced as a safe therapeutic option for coronavirus disease 2019 (COVID-19), while other treatments are developed. Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is not transmissible by transfusion, but bloodborne pathogens remain a risk in regions with high endemic prevalence of disease. Pathogen reduction can mitigate this risk; thus, the objective of this study was to evaluate the effect of riboflavin and ultraviolet light (R + UV) pathogen reduction technology on the functional properties of COVID-19 CP (CCP). Read More

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COVID-19 serology in nephrology healthcare workers.

Wien Klin Wochenschr 2021 Apr 9. Epub 2021 Apr 9.

Division of Nephrology and Dialysis, Department of Medicine III, Medical University of Vienna, Währinger Gürtel 18-20, 1090, Vienna, Austria.

Background: Chronic kidney disease patients show a high mortality in cases of a severe acute respiratory syndrome coronavirus-2 (SARS-CoV‑2) infection. Thus, information on the sero-status of nephrology personnel might be crucial for patient protection; however, limited information exists about the presence of SARS-CoV‑2 antibodies in asymptomatic individuals.

Methods: We examined the seroprevalence of SARS-CoV‑2 IgG and IgM antibodies among healthcare workers of a tertiary care kidney center during the the first peak phase of the corona virus disease 2019 (COVID-19) crisis in Austria using an orthogonal test strategy and a total of 12 commercial nucleocapsid protein or spike glycoprotein-based assays as well as Western blotting and a neutralization assay. Read More

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Neutralization sensitivity of genital tract HIV-1: shift in selective milieu shapes the population available to transmit.

AIDS 2021 Apr 6. Epub 2021 Apr 6.

Division of Immunology, Department of Pathology, University of Cape Town, Cape Town, South Africa International Centre for Genetic Engineering and Biotechnology, Cape Town, Cape Town, South Africa Department of Biological Sciences, School of Science, University of Eldoret, Kenya Division of Medical Virology, Department of Pathology, and Institute of Infectious Diseases and Molecular Medicine, University of Cape Town, Cape Town, South Africa ANOVA Health Institute, Cape Town, Cape Town, South Africa Division of Infectious Diseases and HIV Medicine, Department of Medicine, University of Cape Town, Cape Town, South Africa Division of Medical Virology, Department of Pathology, University of Stellenbosch, Cape Town, South Africa.

Objective: Previous studies indicate that transmitted/founder HIV-1 isolates are sensitive to neutralization by the transmitting donor's antibodies. This is true in at least a subset of sexual transmissions. We investigated whether this selection for neutralization-sensitive variants begins in the genital tract of the donor, prior to transmission. Read More

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SARS-CoV-2 evolution in an immunocompromised host reveals shared neutralization escape mechanisms.

Cell 2021 Mar 16. Epub 2021 Mar 16.

Department of Microbiology, Blavatnik Institute, Harvard Medical School, Boston, MA 02115, USA; Department of Medicine, Division of Infectious Diseases, Brigham and Women's Hospital, Boston, MA 02115, USA; Broad Institute of Harvard and MIT, Cambridge, MA 02142, USA; Massachusetts Consortium on Pathogen Readiness, Boston, MA, USA. Electronic address:

Many individuals mount nearly identical antibody responses to SARS-CoV-2. To gain insight into how the viral spike (S) protein receptor-binding domain (RBD) might evolve in response to common antibody responses, we studied mutations occurring during virus evolution in a persistently infected immunocompromised individual. We use antibody Fab/RBD structures to predict, and pseudotypes to confirm, that mutations found in late-stage evolved S variants confer resistance to a common class of SARS-CoV-2 neutralizing antibodies we isolated from a healthy COVID-19 convalescent donor. Read More

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