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1.
Journal of Clinical Investigation ; 131(21):1-13, 2021.
Article in English | ProQuest Central | ID: covidwho-1503264

ABSTRACT

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is the cause of coronavirus disease 2019 (COVID-19). Little is known about the interplay between preexisting immunity to endemic seasonal coronaviruses and the development of a SARS-CoV-2-specific IgG response. We investigated the kinetics, breadth, magnitude, and level of cross-reactivity of IgG antibodies against SARS-CoV-2 and heterologous seasonal and epidemic coronaviruses at the clonal level in patients with mild or severe COVID-19 as well as in disease control patients. We assessed antibody reactivity to nucleocapsid and spike antigens and correlated this IgG response to SARS-CoV-2 neutralization. Patients with COVID-19 mounted a mostly type-specific SARS-CoV-2 response. Additionally, IgG clones directed against a seasonal coronavirus were boosted in patients with severe COVID-19. These boosted clones showed limited cross-reactivity and did not neutralize SARS-CoV-2. These findings indicate a boost of poorly protective CoV-specific antibodies in patients with COVID-19 that correlated with disease severity, revealing "original antigenic sin."

2.
Nat Commun ; 11(1): 2511, 2020 05 14.
Article in English | MEDLINE | ID: covidwho-1387317

ABSTRACT

An amendment to this paper has been published and can be accessed via a link at the top of the paper.

3.
Proc Natl Acad Sci U S A ; 118(28)2021 07 13.
Article in English | MEDLINE | ID: covidwho-1284760

ABSTRACT

Severe acute respiratory syndrome (SARS) coronavirus 2 (SARS-CoV-2) has emerged as the infectious agent causing the pandemic coronavirus disease 2019 (COVID-19) with dramatic consequences for global human health and economics. Previously, we reached clinical evaluation with our vector vaccine based on modified vaccinia virus Ankara (MVA) against the Middle East respiratory syndrome coronavirus (MERS-CoV), which causes an infection in humans similar to SARS and COVID-19. Here, we describe the construction and preclinical characterization of a recombinant MVA expressing full-length SARS-CoV-2 spike (S) protein (MVA-SARS-2-S). Genetic stability and growth characteristics of MVA-SARS-2-S, plus its robust expression of S protein as antigen, make it a suitable candidate vaccine for industrial-scale production. Vaccinated mice produced S-specific CD8+ T cells and serum antibodies binding to S protein that neutralized SARS-CoV-2. Prime-boost vaccination with MVA-SARS-2-S protected mice sensitized with a human ACE2-expressing adenovirus from SARS-CoV-2 infection. MVA-SARS-2-S is currently being investigated in a phase I clinical trial as aspirant for developing a safe and efficacious vaccine against COVID-19.


Subject(s)
Antibodies, Neutralizing/immunology , Antibodies, Viral/immunology , COVID-19 Vaccines/immunology , COVID-19/prevention & control , Spike Glycoprotein, Coronavirus/immunology , Animals , COVID-19 Vaccines/standards , Dose-Response Relationship, Immunologic , Humans , Mice , Mice, Inbred BALB C , SARS-CoV-2 , Spike Glycoprotein, Coronavirus/genetics , T-Lymphocytes , Vaccination , Vaccinia virus
4.
J Infect Dis ; 223(12): 2020-2028, 2021 06 15.
Article in English | MEDLINE | ID: covidwho-1246725

ABSTRACT

Effective clinical intervention strategies for coronavirus disease 2019 (COVID-19) are urgently needed. Although several clinical trials have evaluated use of convalescent plasma containing virus-neutralizing antibodies, levels of neutralizing antibodies are usually not assessed and the effectiveness has not been proven. We show that hamsters treated prophylactically with a 1:2560 titer of human convalescent plasma or a 1:5260 titer of monoclonal antibody were protected against weight loss, had a significant reduction of virus replication in the lungs, and showed reduced pneumonia. Interestingly, this protective effect was lost with a titer of 1:320 of convalescent plasma. These data highlight the importance of screening plasma donors for high levels of neutralizing antibodies. Our data show that prophylactic administration of high levels of neutralizing antibody, either monoclonal or from convalescent plasma, prevent severe SARS-CoV-2 pneumonia in a hamster model, and could be used as an alternative or complementary to other antiviral treatments for COVID-19.


Subject(s)
Antibodies, Monoclonal/therapeutic use , Antibodies, Neutralizing/therapeutic use , COVID-19/therapy , Lung/pathology , SARS-CoV-2/immunology , Virus Replication/drug effects , Animals , Antibodies, Monoclonal/administration & dosage , Antibodies, Neutralizing/administration & dosage , COVID-19/immunology , Cricetinae , Disease Models, Animal , Humans , Immunization, Passive , Lung/drug effects , Virus Shedding/drug effects , Weight Loss/drug effects
5.
Nat Commun ; 12(1): 3189, 2021 05 27.
Article in English | MEDLINE | ID: covidwho-1246368

ABSTRACT

In a randomized clinical trial of 86 hospitalized COVID-19 patients comparing standard care to treatment with 300mL convalescent plasma containing high titers of neutralizing SARS-CoV-2 antibodies, no overall clinical benefit was observed. Using a comprehensive translational approach, we unravel the virological and immunological responses following treatment to disentangle which COVID-19 patients may benefit and should be the focus of future studies. Convalescent plasma is safe, does not improve survival, has no effect on the disease course, nor does plasma enhance viral clearance in the respiratory tract, influence SARS-CoV-2 antibody development or serum proinflammatory cytokines levels. Here, we show that the vast majority of patients already had potent neutralizing SARS-CoV-2 antibodies at hospital admission and with comparable titers to carefully selected plasma donors. This resulted in the decision to terminate the trial prematurely. Treatment with convalescent plasma should be studied early in the disease course or at least preceding autologous humoral response development.


Subject(s)
Antibodies, Neutralizing/immunology , Antibodies, Viral/immunology , COVID-19/immunology , COVID-19/therapy , Cytokines/blood , SARS-CoV-2/immunology , Aged , Antibodies, Neutralizing/blood , Antibodies, Viral/blood , Blood Donors , COVID-19/blood , COVID-19/virology , Disease Progression , Female , Hospitalization , Humans , Immunization, Passive , Immunoglobulin G/blood , Kaplan-Meier Estimate , Male , Middle Aged , Spike Glycoprotein, Coronavirus/immunology , Treatment Outcome
6.
Eur J Immunol ; 51(7): 1774-1784, 2021 07.
Article in English | MEDLINE | ID: covidwho-1151899

ABSTRACT

Optimal vaccines are needed for sustained suppression of SARS-CoV-2 and other novel coronaviruses. Here, we developed a recombinant type 5 adenovirus vector encoding the gene for the SARS-CoV-2 S1 subunit antigen (Ad5.SARS-CoV-2-S1) for COVID-19 immunization and evaluated its immunogenicity in mice. A single immunization with Ad5.SARS-CoV-2-S1 via S.C. injection or I.N delivery induced robust antibody and cellular immune responses. Vaccination elicited significant S1-specific IgG, IgG1, and IgG2a endpoint titers as early as 2 weeks, and the induced antibodies were long lasting. I.N. and S.C. administration of Ad5.SARS-CoV-2-S1 produced S1-specific GC B cells in cervical and axillary LNs, respectively. Moreover, I.N. and S.C. immunization evoked significantly greater antigen-specific T-cell responses compared to unimmunized control groups with indications that S.C. injection was more effective than I.N. delivery in eliciting cellular immune responses. Mice vaccinated by either route demonstrated significantly increased virus-specific neutralization antibodies on weeks 8 and 12 compared to control groups, as well as BM antibody forming cells (AFC), indicative of long-term immunity. Thus, this Ad5-vectored SARS-CoV-2 vaccine candidate showed promising immunogenicity following delivery to mice by S.C. and I.N. routes of administration, supporting the further development of Ad-based vaccines against COVID-19 and other infectious diseases for sustainable global immunization programs.


Subject(s)
COVID-19 Vaccines/immunology , COVID-19/immunology , COVID-19/prevention & control , SARS-CoV-2/immunology , Spike Glycoprotein, Coronavirus/immunology , Adenoviridae/genetics , Adenoviridae/immunology , Animals , Antibodies, Neutralizing/blood , Antibodies, Neutralizing/immunology , Antibodies, Viral/blood , Antibodies, Viral/immunology , B-Lymphocytes/immunology , Immunity, Cellular/immunology , Immunity, Humoral/immunology , Immunoglobulin G/immunology , Mice , Mice, Inbred BALB C , SARS-CoV-2/genetics , Spike Glycoprotein, Coronavirus/genetics , T-Lymphocytes/immunology , Vaccination
7.
Nat Commun ; 12(1): 1715, 2021 03 17.
Article in English | MEDLINE | ID: covidwho-1139739

ABSTRACT

The coronavirus spike glycoprotein, located on the virion surface, is the key mediator of cell entry and the focus for development of protective antibodies and vaccines. Structural studies show exposed sites on the spike trimer that might be targeted by antibodies with cross-species specificity. Here we isolated two human monoclonal antibodies from immunized humanized mice that display a remarkable cross-reactivity against distinct spike proteins of betacoronaviruses including SARS-CoV, SARS-CoV-2, MERS-CoV and the endemic human coronavirus HCoV-OC43. Both cross-reactive antibodies target the stem helix in the spike S2 fusion subunit which, in the prefusion conformation of trimeric spike, forms a surface exposed membrane-proximal helical bundle. Both antibodies block MERS-CoV infection in cells and provide protection to mice from lethal MERS-CoV challenge in prophylactic and/or therapeutic models. Our work highlights an immunogenic and vulnerable site on the betacoronavirus spike protein enabling elicitation of antibodies with unusual binding breadth.


Subject(s)
Antibodies, Monoclonal, Humanized/immunology , Betacoronavirus/immunology , Epitopes/immunology , Spike Glycoprotein, Coronavirus/immunology , Animals , Antibodies, Monoclonal, Humanized/therapeutic use , Antibodies, Neutralizing/immunology , Antibodies, Neutralizing/therapeutic use , Antibodies, Viral/immunology , Betacoronavirus/classification , Camelus , Coronavirus Infections/drug therapy , Coronavirus Infections/virology , Cross Reactions , Epitopes/chemistry , Epitopes/genetics , Humans , Mice , Protein Conformation , Protein Subunits , Spike Glycoprotein, Coronavirus/chemistry , Spike Glycoprotein, Coronavirus/genetics
8.
Lancet Infect Dis ; 20(7): 827-838, 2020 07.
Article in English | MEDLINE | ID: covidwho-1103186

ABSTRACT

BACKGROUND: The Middle East respiratory syndrome coronavirus (MERS-CoV) causes a respiratory disease with a case fatality rate of up to 35%. Given its potential to cause a public health emergency and the absence of efficacious drugs or vaccines, MERS is one of the WHO priority diseases warranting urgent research and development of countermeasures. We aimed to assess safety and tolerability of an anti-MERS-CoV modified vaccinia virus Ankara (MVA)-based vaccine candidate that expresses the MERS-CoV spike glycoprotein, MVA-MERS-S, in healthy adults. METHODS: This open-label, phase 1 trial was done at the University Medical Center Hamburg-Eppendorf (Hamburg, Germany). Participants were healthy men and women aged 18-55 years with no clinically significant health problems as determined during medical history and physical examination, a body-mass index of 18·5-30·0 kg/m2 and weight of more than 50 kg at screening, and a negative pregnancy test for women. A key exclusion criterion was a previous MVA vaccination. For the prime immunisation, participants received doses of 1 × 107 plaque-forming unit (PFU; low-dose group) or 1 × 108 PFU (high-dose group) MVA-MERS-S intramuscularly. A second identical dose was administered intramuscularly as a booster immunisation 28 days after first injection. As a control group for immunogenicity analyses, blood samples were drawn at identical study timepoints from six healthy adults, who did not receive any injections. The primary objectives of the study were safety and tolerability of the two dosage levels and reactogenicity after administration. Immunogenicity was assessed as a secondary endpoint by ELISA and neutralisation tests. T-cell immunity was evaluated by interferon-γ-linked enzyme-linked immune absorbent spot assay. All participants who were vaccinated at least once were included in the safety analysis. Immunogenicity was analysed in the participants who completed 6 months of follow-up. This trial is registered with ClinicalTrials.gov, NCT03615911, and EudraCT, 2014-003195-23 FINDINGS: From Dec 17, 2017, to June 5, 2018, 26 participants (14 in the low-dose group and 12 in the high-dose group) were enrolled and received the first dose of the vaccine according to their group allocation. Of these, 23 participants (12 in the low-dose group and 11 in the high-dose group) received a second dose of MVA-MERS-S according to their group allocation after a 28-day interval and completed follow-up. Homologous prime-boost immunisation with MVA-MERS-S revealed a benign safety profile with only transient mild-to-moderate reactogenicity. Participants had no severe or serious adverse events. 67 vaccine-related adverse events were reported in ten (71%) of 14 participants in the low-dose group, and 111 were reported in ten (83%) of 12 participants in the high-dose group. Solicited local reactions were the most common adverse events: pain was observed in 17 (65%; seven in the low-dose group vs ten in the high-dose group) participants, swelling in ten (38%; two vs eight) participants, and induration in ten (38%; one vs nine) participants. Headaches (observed in seven participants in the low-dose group vs nine in the high-dose group) and fatigue or malaise (ten vs seven participants) were the most common solicited systemic adverse events. All adverse events resolved swiftly (within 1-3 days) and without sequelae. Following booster immunisation, nine (75%) of 12 participants in the low-dose group and 11 (100%) participants in the high-dose group showed seroconversion using a MERS-CoV S1 ELISA at any timepoint during the study. Binding antibody titres correlated with MERS-CoV-specific neutralising antibodies (Spearman's correlation r=0·86 [95% CI 0·6960-0·9427], p=0·0001). MERS-CoV spike-specific T-cell responses were detected in ten (83%) of 12 immunised participants in the low-dose group and ten (91%) of 11 immunised participants in the high-dose group. INTERPRETATION: Vaccination with MVA-MERS-S had a favourable safety profile without serious or severe adverse events. Homologous prime-boost immunisation induced humoral and cell-mediated responses against MERS-CoV. A dose-effect relationship was demonstrated for reactogenicity, but not for vaccine-induced immune responses. The data presented here support further clinical testing of MVA-MERS-S in larger cohorts to advance MERS vaccine development. FUNDING: German Center for Infection Research.


Subject(s)
Coronavirus Infections/immunology , Dose-Response Relationship, Immunologic , Immunogenicity, Vaccine , Vaccinia virus/genetics , Viral Vaccines/immunology , Adult , Antibodies, Viral/blood , Coronavirus Infections/genetics , Coronavirus Infections/prevention & control , Enzyme-Linked Immunosorbent Assay , Female , Genetic Vectors , Germany , Humans , Immunization, Secondary , Male , Middle Aged , Middle East Respiratory Syndrome Coronavirus/immunology , Neutralization Tests , Vaccines, DNA , Young Adult
9.
Cell ; 184(5): 1188-1200.e19, 2021 03 04.
Article in English | MEDLINE | ID: covidwho-1046538

ABSTRACT

The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) pandemic is continuing to disrupt personal lives, global healthcare systems, and economies. Hence, there is an urgent need for a vaccine that prevents viral infection, transmission, and disease. Here, we present a two-component protein-based nanoparticle vaccine that displays multiple copies of the SARS-CoV-2 spike protein. Immunization studies show that this vaccine induces potent neutralizing antibody responses in mice, rabbits, and cynomolgus macaques. The vaccine-induced immunity protects macaques against a high-dose challenge, resulting in strongly reduced viral infection and replication in the upper and lower airways. These nanoparticles are a promising vaccine candidate to curtail the SARS-CoV-2 pandemic.


Subject(s)
COVID-19 Vaccines/administration & dosage , COVID-19 Vaccines/immunology , Macaca fascicularis , Spike Glycoprotein, Coronavirus/chemistry , Animals , Antibodies, Neutralizing , B-Lymphocytes/immunology , COVID-19/immunology , COVID-19/prevention & control , Mice , Mice, Inbred BALB C , Models, Animal , Nanoparticles/administration & dosage , Rabbits , SARS-CoV-2/physiology , Spike Glycoprotein, Coronavirus/blood , T-Lymphocytes/immunology , Viral Load
10.
Emerg Microbes Infect ; 10(1): 1-7, 2021 Dec.
Article in English | MEDLINE | ID: covidwho-990475

ABSTRACT

Transmission of severe acute respiratory coronavirus-2 (SARS-CoV-2) between livestock and humans is a potential public health concern. We demonstrate the susceptibility of rabbits to SARS-CoV-2, which excrete infectious virus from the nose and throat upon experimental inoculation. Therefore, investigations on the presence of SARS-CoV-2 in farmed rabbits should be considered.


Subject(s)
COVID-19/transmission , Rabbits/virology , SARS-CoV-2/isolation & purification , Angiotensin-Converting Enzyme 2/physiology , Animals , COVID-19/etiology , COVID-19/veterinary , Disease Susceptibility/veterinary , Female , HEK293 Cells , Humans , Virus Shedding
12.
Emerg Infect Dis ; 26(7):1478-1488, 2020.
Article in English | MEDLINE | ID: covidwho-655091

ABSTRACT

A new coronavirus, severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), has recently emerged to cause a human pandemic. Although molecular diagnostic tests were rapidly developed, serologic assays are still lacking, yet urgently needed. Validated serologic assays are needed for contact tracing, identifying the viral reservoir, and epidemiologic studies. We developed serologic assays for detection of SARS-CoV-2 neutralizing, spike protein-specific, and nucleocapsid-specific antibodies. Using serum samples from patients with PCR-confirmed SARS-CoV-2 infections, other coronaviruses, or other respiratory pathogenic infections, we validated and tested various antigens in different in-house and commercial ELISAs. We demonstrated that most PCR-confirmed SARS-CoV-2-infected persons seroconverted by 2 weeks after disease onset. We found that commercial S1 IgG or IgA ELISAs were of lower specificity, and sensitivity varied between the 2 assays;the IgA ELISA showed higher sensitivity. Overall, the validated assays described can be instrumental for detection of SARS-CoV-2-specific antibodies for diagnostic, seroepidemiologic, and vaccine evaluation studies.

13.
Nat Commun ; 11(1): 3496, 2020 07 08.
Article in English | MEDLINE | ID: covidwho-640239

ABSTRACT

SARS-CoV-2, a coronavirus that emerged in late 2019, has spread rapidly worldwide, and information about the modes of transmission of SARS-CoV-2 among humans is critical to apply appropriate infection control measures and to slow its spread. Here we show that SARS-CoV-2 is transmitted efficiently via direct contact and via the air (via respiratory droplets and/or aerosols) between ferrets, 1 to 3 days and 3 to 7 days after exposure respectively. The pattern of virus shedding in the direct contact and indirect recipient ferrets is similar to that of the inoculated ferrets and infectious virus is isolated from all positive animals, showing that ferrets are productively infected via either route. This study provides experimental evidence of robust transmission of SARS-CoV-2 via the air, supporting the implementation of community-level social distancing measures currently applied in many countries in the world and informing decisions on infection control measures in healthcare settings.


Subject(s)
Betacoronavirus/physiology , Coronavirus Infections/transmission , Coronavirus Infections/virology , Pneumonia, Viral/transmission , Pneumonia, Viral/virology , Animals , Antibodies, Viral/blood , Betacoronavirus/genetics , Betacoronavirus/immunology , Betacoronavirus/isolation & purification , COVID-19 , Disease Models, Animal , Ferrets , Genome, Viral/genetics , Humans , Pandemics , Rectum/virology , Respiratory System/virology , SARS-CoV-2 , Sequence Analysis, RNA , Virus Shedding
14.
Nat Commun ; 11(1): 3436, 2020 07 06.
Article in English | MEDLINE | ID: covidwho-630511

ABSTRACT

The world is entering a new era of the COVID-19 pandemic in which there is an increasing call for reliable antibody testing. To support decision making on the deployment of serology for either population screening or diagnostics, we present a detailed comparison of serological COVID-19 assays. We show that among the selected assays there is a wide diversity in assay performance in different scenarios and when correlated to virus neutralizing antibodies. The Wantai ELISA detecting total immunoglobulins against the receptor binding domain of SARS CoV-2, has the best overall characteristics to detect functional antibodies in different stages and severity of disease, including the potential to set a cut-off indicating the presence of protective antibodies. The large variety of available serological assays requires proper assay validation before deciding on deployment of assays for specific applications.


Subject(s)
Antibodies, Viral/blood , Coronavirus Infections/diagnosis , Pneumonia, Viral/diagnosis , Serologic Tests/standards , Antibodies, Neutralizing/blood , Betacoronavirus , COVID-19 , COVID-19 Testing , Clinical Laboratory Techniques , Enzyme-Linked Immunosorbent Assay , High-Throughput Screening Assays , Humans , Luminescent Measurements , Neutralization Tests , Pandemics , SARS-CoV-2 , Sensitivity and Specificity
15.
Sci Immunol ; 5(48)2020 06 26.
Article in English | MEDLINE | ID: covidwho-617063

ABSTRACT

SARS-CoV-2 has been identified as the causative agent of a global outbreak of respiratory tract disease (COVID-19). In some patients the infection results in moderate to severe acute respiratory distress syndrome (ARDS), requiring invasive mechanical ventilation. High serum levels of IL-6, IL-10 and an immune hyperresponsiveness referred to as a 'cytokine storm' have been associated with poor clinical outcome. Despite the large numbers of COVID-19 cases and deaths, information on the phenotype and kinetics of SARS-CoV-2-specific T cells is limited. Here, we studied 10 COVID-19 patients who required admission to an intensive care unit and detected SARS-CoV-2-specific CD4+ and CD8+ T cells in 10 out of 10 and 8 out of 10 patients, respectively. We also detected low levels of SARS-CoV-2-reactive T cells in 2 out of 10 healthy controls not previously exposed to SARS-CoV-2, which is indicative of cross-reactivity due to past infection with 'common cold' coronaviruses. The strongest T-cell responses were directed to the spike (S) surface glycoprotein, and SARS-CoV-2-specific T cells predominantly produced effector and Th1 cytokines, although Th2 and Th17 cytokines were also detected. Furthermore, we studied T-cell kinetics and showed that SARS-CoV-2-specific T cells are present relatively early and increase over time. Collectively, these data shed light on the potential variations in T-cell responses as a function of disease severity, an issue that is key to understanding the potential role of immunopathology in the disease, and also inform vaccine design and evaluation.


Subject(s)
Betacoronavirus/immunology , CD4-Positive T-Lymphocytes/immunology , CD8-Positive T-Lymphocytes/immunology , Coronavirus Infections/immunology , Phenotype , Pneumonia, Viral/immunology , Respiratory Distress Syndrome/immunology , Aged , COVID-19 , Cells, Cultured , Coronavirus Infections/blood , Coronavirus Infections/virology , Cytokines/metabolism , Female , Humans , Immunologic Memory , Kinetics , Longitudinal Studies , Male , Middle Aged , Pandemics , Pneumonia, Viral/blood , Pneumonia, Viral/virology , Respiratory Distress Syndrome/blood , Respiratory Distress Syndrome/virology , SARS-CoV-2 , Severity of Illness Index , Spike Glycoprotein, Coronavirus/immunology , Viral Load/immunology
16.
Science ; 369(6504): 643-650, 2020 08 07.
Article in English | MEDLINE | ID: covidwho-599037

ABSTRACT

The rapid spread of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has had a large impact on global health, travel, and economy. Therefore, preventative and therapeutic measures are urgently needed. Here, we isolated monoclonal antibodies from three convalescent coronavirus disease 2019 (COVID-19) patients using a SARS-CoV-2 stabilized prefusion spike protein. These antibodies had low levels of somatic hypermutation and showed a strong enrichment in VH1-69, VH3-30-3, and VH1-24 gene usage. A subset of the antibodies was able to potently inhibit authentic SARS-CoV-2 infection at a concentration as low as 0.007 micrograms per milliliter. Competition and electron microscopy studies illustrate that the SARS-CoV-2 spike protein contains multiple distinct antigenic sites, including several receptor-binding domain (RBD) epitopes as well as non-RBD epitopes. In addition to providing guidance for vaccine design, the antibodies described here are promising candidates for COVID-19 treatment and prevention.


Subject(s)
Antibodies, Monoclonal/immunology , Antibodies, Neutralizing/immunology , Antibodies, Viral/immunology , Betacoronavirus/immunology , Coronavirus Infections/immunology , Pneumonia, Viral/immunology , Spike Glycoprotein, Coronavirus/immunology , Adult , Aged , Antibodies, Neutralizing/blood , Antibodies, Viral/blood , Antibody Affinity , Antigens, Viral/immunology , B-Lymphocyte Subsets/immunology , Broadly Neutralizing Antibodies/immunology , COVID-19 , Cell Line, Tumor , Coronavirus Infections/prevention & control , Coronavirus Infections/therapy , Epitopes/immunology , Female , Humans , Immunologic Memory , Immunophenotyping , Male , Middle Aged , Pandemics/prevention & control , Pneumonia, Viral/prevention & control , Pneumonia, Viral/therapy , Protein Domains , Protein Interaction Domains and Motifs/immunology , Receptors, Coronavirus , Receptors, Virus/metabolism , SARS-CoV-2 , Spike Glycoprotein, Coronavirus/chemistry
17.
Emerg Microbes Infect ; 9(1): 1080-1091, 2020 Dec.
Article in English | MEDLINE | ID: covidwho-429885

ABSTRACT

Middle East respiratory syndrome coronavirus (MERS-CoV) is a WHO priority pathogen for which vaccines are urgently needed. Using an immune-focusing approach, we created self-assembling particles multivalently displaying critical regions of the MERS-CoV spike protein ─fusion peptide, heptad repeat 2, and receptor binding domain (RBD) ─ and tested their immunogenicity and protective capacity in rabbits. Using a "plug-and-display" SpyTag/SpyCatcher system, we coupled RBD to lumazine synthase (LS) particles producing multimeric RBD-presenting particles (RBD-LS). RBD-LS vaccination induced antibody responses of high magnitude and quality (avidity, MERS-CoV neutralizing capacity, and mucosal immunity) with cross-clade neutralization. The antibody responses were associated with blocking viral replication and upper and lower respiratory tract protection against MERS-CoV infection in rabbits. This arrayed multivalent presentation of the viral RBD using the antigen-SpyTag/LS-SpyCatcher is a promising MERS-CoV vaccine candidate and this platform may be applied for the rapid development of vaccines against other emerging viruses such as SARS-CoV-2.


Subject(s)
Antibody Formation , Antigen Presentation , Coronavirus Infections/immunology , Spike Glycoprotein, Coronavirus/immunology , Viral Vaccines/immunology , Animals , Antibodies, Neutralizing/immunology , Antibodies, Viral/immunology , Antibody Affinity , Binding Sites , Coronavirus Infections/prevention & control , Enzyme-Linked Immunosorbent Assay , Female , Genetic Vectors , HEK293 Cells , Humans , Immunogenicity, Vaccine , Middle East Respiratory Syndrome Coronavirus/immunology , Middle East Respiratory Syndrome Coronavirus/physiology , Neutralization Tests , Protein Binding , Protein Domains , Rabbits , Spike Glycoprotein, Coronavirus/biosynthesis , Virus Replication
18.
Viruses ; 12(4)2020 04 03.
Article in English | MEDLINE | ID: covidwho-326670

ABSTRACT

Middle East respiratory syndrome (MERS) is a respiratory disease caused by a zoonotic coronavirus (MERS-CoV). Camel handlers, including slaughterhouse workers and herders, are at risk of acquiring MERS-CoV infections. However, there is limited evidence of infections among camel handlers in Africa. The purpose of this study was to determine the presence of antibodies to MERS-CoV in high-risk groups in Kenya. Sera collected from 93 camel handlers, 58 slaughterhouse workers and 35 camel herders, were screened for MERS-CoV antibodies using ELISA and PRNT. We found four seropositive slaughterhouse workers by PRNT. Risk factors amongst the slaughterhouse workers included being the slaughterman (the person who cuts the throat of the camel) and drinking camel blood. Further research is required to understand the epidemiology of MERS-CoV in Africa in relation to occupational risk, with a need for additional studies on the transmission of MERS-CoV from dromedary camels to humans, seroprevalence and associated risk factors.


Subject(s)
Antibodies, Viral/blood , Coronavirus Infections/epidemiology , Coronavirus Infections/transmission , Middle East Respiratory Syndrome Coronavirus/immunology , Abattoirs , Adult , Animals , Antibodies, Neutralizing/blood , Camelus/virology , Disease Reservoirs/virology , Enzyme-Linked Immunosorbent Assay , Humans , Kenya/epidemiology , Male , Occupational Exposure , Reverse Transcriptase Polymerase Chain Reaction , Seroepidemiologic Studies , Zoonoses/virology
19.
Nat Commun ; 11(1): 2251, 2020 05 04.
Article in English | MEDLINE | ID: covidwho-164588

ABSTRACT

The emergence of the novel human coronavirus SARS-CoV-2 in Wuhan, China has caused a worldwide epidemic of respiratory disease (COVID-19). Vaccines and targeted therapeutics for treatment of this disease are currently lacking. Here we report a human monoclonal antibody that neutralizes SARS-CoV-2 (and SARS-CoV) in cell culture. This cross-neutralizing antibody targets a communal epitope on these viruses and may offer potential for prevention and treatment of COVID-19.


Subject(s)
Antibodies, Monoclonal/immunology , Antibodies, Neutralizing/immunology , Antibodies, Viral/immunology , Betacoronavirus/immunology , Coronavirus Infections/immunology , Coronavirus Infections/prevention & control , Pandemics/prevention & control , Pneumonia, Viral/immunology , Pneumonia, Viral/prevention & control , Angiotensin-Converting Enzyme 2 , Animals , Antibodies, Monoclonal/pharmacology , Antibodies, Neutralizing/pharmacology , Antibodies, Viral/pharmacology , Antibody Affinity/immunology , Betacoronavirus/chemistry , Betacoronavirus/drug effects , COVID-19 , Chlorocebus aethiops , Conserved Sequence , Coronavirus Infections/drug therapy , Coronavirus Infections/virology , Cross Reactions/immunology , Epitopes, B-Lymphocyte/chemistry , Epitopes, B-Lymphocyte/immunology , Humans , In Vitro Techniques , Inhibitory Concentration 50 , Models, Molecular , Peptidyl-Dipeptidase A/chemistry , Peptidyl-Dipeptidase A/metabolism , Pneumonia, Viral/drug therapy , Pneumonia, Viral/virology , Protein Binding/drug effects , Protein Domains/immunology , Receptors, Virus/chemistry , Receptors, Virus/metabolism , SARS Virus/chemistry , SARS Virus/drug effects , SARS Virus/immunology , SARS-CoV-2 , Spike Glycoprotein, Coronavirus/chemistry , Spike Glycoprotein, Coronavirus/immunology , Vero Cells
20.
Science ; 368(6494): 1012-1015, 2020 05 29.
Article in English | MEDLINE | ID: covidwho-71867

ABSTRACT

The current pandemic coronavirus, severe acute respiratory syndrome-coronavirus 2 (SARS-CoV-2), was recently identified in patients with an acute respiratory syndrome, coronavirus disease 2019 (COVID-19). To compare its pathogenesis with that of previously emerging coronaviruses, we inoculated cynomolgus macaques with SARS-CoV-2 or Middle East respiratory syndrome (MERS)-CoV and compared the pathology and virology with historical reports of SARS-CoV infections. In SARS-CoV-2-infected macaques, virus was excreted from nose and throat in the absence of clinical signs and detected in type I and II pneumocytes in foci of diffuse alveolar damage and in ciliated epithelial cells of nasal, bronchial, and bronchiolar mucosae. In SARS-CoV infection, lung lesions were typically more severe, whereas they were milder in MERS-CoV infection, where virus was detected mainly in type II pneumocytes. These data show that SARS-CoV-2 causes COVID-19-like disease in macaques and provides a new model to test preventive and therapeutic strategies.


Subject(s)
Betacoronavirus/pathogenicity , Coronavirus Infections/pathology , Coronavirus Infections/virology , Disease Models, Animal , Lung/pathology , Macaca fascicularis , Pneumonia, Viral/pathology , Pneumonia, Viral/virology , Aging , Animals , Betacoronavirus/isolation & purification , Betacoronavirus/physiology , COVID-19 , Female , Lung/virology , Middle East Respiratory Syndrome Coronavirus/isolation & purification , Middle East Respiratory Syndrome Coronavirus/physiology , Pandemics , Pulmonary Alveoli/pathology , Pulmonary Alveoli/virology , Respiratory System/pathology , Respiratory System/virology , SARS Virus/isolation & purification , SARS Virus/physiology , SARS-CoV-2 , Severe Acute Respiratory Syndrome/pathology , Severe Acute Respiratory Syndrome/virology , Virus Replication , Virus Shedding
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