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1.
Front Immunol ; 12: 781280, 2021.
Article in English | MEDLINE | ID: covidwho-1608387

ABSTRACT

The development of more effective, accessible, and easy to administer COVID-19 vaccines next to the currently marketed mRNA, viral vector, and whole inactivated virus vaccines is essential to curtailing the SARS-CoV-2 pandemic. A major concern is reduced vaccine-induced immune protection to emerging variants, and therefore booster vaccinations to broaden and strengthen the immune response might be required. Currently, all registered COVID-19 vaccines and the majority of COVID-19 vaccines in development are intramuscularly administered, targeting the induction of systemic immunity. Intranasal vaccines have the capacity to induce local mucosal immunity as well, thereby targeting the primary route of viral entry of SARS-CoV-2 with the potential of blocking transmission. Furthermore, intranasal vaccines offer greater practicality in terms of cost and ease of administration. Currently, only eight out of 112 vaccines in clinical development are administered intranasally. We developed an intranasal COVID-19 subunit vaccine, based on a recombinant, six-proline-stabilized, D614G spike protein (mC-Spike) of SARS-CoV-2 linked via the LPS-binding peptide sequence mCramp (mC) to outer membrane vesicles (OMVs) from Neisseria meningitidis. The spike protein was produced in CHO cells, and after linking to the OMVs, the OMV-mC-Spike vaccine was administered to mice and Syrian hamsters via intranasal or intramuscular prime-boost vaccinations. In all animals that received OMV-mC-Spike, serum-neutralizing antibodies were induced upon vaccination. Importantly, high levels of spike-binding immunoglobulin G (IgG) and A (IgA) antibodies in the nose and lungs were only detected in intranasally vaccinated animals, whereas intramuscular vaccination only induced an IgG response in the serum. Two weeks after their second vaccination, hamsters challenged with SARS-CoV-2 were protected from weight loss and viral replication in the lungs compared to the control groups vaccinated with OMV or spike alone. Histopathology showed no lesions in lungs 7 days after challenge in OMV-mC-Spike-vaccinated hamsters, whereas the control groups did show pathological lesions in the lung. The OMV-mC-Spike candidate vaccine data are very promising and support further development of this novel non-replicating, needle-free, subunit vaccine concept for clinical testing.


Subject(s)
COVID-19 Vaccines/immunology , COVID-19/immunology , Immunity, Mucosal/immunology , SARS-CoV-2/immunology , Administration, Intranasal , Animals , Antibodies, Neutralizing/immunology , Antibodies, Viral/immunology , COVID-19/epidemiology , COVID-19/virology , COVID-19 Vaccines/administration & dosage , Cytoplasmic Vesicles/immunology , Female , Humans , Immunoglobulin A/immunology , Mesocricetus , Mice, Inbred BALB C , Neisseria meningitidis/immunology , Pandemics/prevention & control , SARS-CoV-2/metabolism , SARS-CoV-2/physiology , Spike Glycoprotein, Coronavirus/immunology , Spike Glycoprotein, Coronavirus/metabolism , Vaccination/methods , Vaccines, Subunit/administration & dosage , Vaccines, Subunit/immunology
2.
MAbs ; 14(1): 2002236, 2022.
Article in English | MEDLINE | ID: covidwho-1585298

ABSTRACT

Coronavirus disease 2019 (COVID-19) is an evolving global public health crisis in need of therapeutic options. Passive immunization of monoclonal antibodies (mAbs) represents a promising therapeutic strategy capable of conferring immediate protection from SARS-CoV-2 infection. Herein, we describe the discovery and characterization of neutralizing SARS-CoV-2 IgG and VHH antibodies from four large-scale phage libraries. Each library was constructed synthetically with shuffled complementarity-determining region loops from natural llama and human antibody repertoires. While most candidates targeted the receptor-binding domain of the S1 subunit of SARS-CoV-2 spike protein, we also identified a neutralizing IgG candidate that binds a unique epitope on the N-terminal domain. A select number of antibodies retained binding to SARS-CoV-2 variants Alpha, Beta, Gamma, Kappa and Delta. Overall, our data show that synthetic phage libraries can rapidly yield SARS-CoV-2 S1 antibodies with therapeutically desirable features, including high affinity, unique binding sites, and potent neutralizing activity in vitro, and a capacity to limit disease in vivo.


Subject(s)
Antibodies, Neutralizing/immunology , Antibodies, Viral/immunology , COVID-19/immunology , Cell Surface Display Techniques , Immunoglobulin G/immunology , Peptide Library , SARS-CoV-2/immunology , Single-Domain Antibodies/immunology , Spike Glycoprotein, Coronavirus/immunology , Animals , Antibodies, Neutralizing/genetics , Antibodies, Neutralizing/metabolism , Antibodies, Neutralizing/pharmacology , Antibodies, Viral/genetics , Antibodies, Viral/metabolism , Antibody Specificity , Binding Sites, Antibody , COVID-19/metabolism , COVID-19/prevention & control , COVID-19/virology , Chlorocebus aethiops , Disease Models, Animal , Epitopes , Female , Host-Pathogen Interactions , Immunoglobulin G/genetics , Immunoglobulin G/metabolism , Immunoglobulin G/pharmacology , Mesocricetus , SARS-CoV-2/pathogenicity , Single-Domain Antibodies/genetics , Single-Domain Antibodies/metabolism , Single-Domain Antibodies/pharmacology , Vero Cells
3.
Gut Microbes ; 14(1): 2018900, 2022.
Article in English | MEDLINE | ID: covidwho-1585291

ABSTRACT

Mounting evidence suggests that the gut-to-lung axis is critical during respiratory viral infections. We herein hypothesized that disruption of gut homeostasis during severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection may associate with early disease outcomes. To address this question, we took advantage of the Syrian hamster model. Our data confirmed that this model recapitulates some hallmark features of the human disease in the lungs. We further showed that SARS-CoV-2 infection associated with mild intestinal inflammation, relative alteration in intestinal barrier property and liver inflammation and altered lipid metabolism. These changes occurred concomitantly with an alteration of the gut microbiota composition over the course of infection, notably characterized by a higher relative abundance of deleterious bacterial taxa such as Enterobacteriaceae and Desulfovibrionaceae. Conversely, several members of the Ruminococcaceae and Lachnospiraceae families, including bacteria known to produce the fermentative products short-chain fatty acids (SCFAs), had a reduced relative proportion compared to non-infected controls. Accordingly, infection led to a transient decrease in systemic SCFA amounts. SCFA supplementation during infection had no effect on clinical and inflammatory parameters. Lastly, a strong correlation between some gut microbiota taxa and clinical and inflammation indices of SARS-CoV-2 infection severity was evidenced. Collectively, alteration of the gut microbiota correlates with disease severity in hamsters making this experimental model valuable for the design of interventional, gut microbiota-targeted, approaches for the control of COVID-19.Abbreviations: SARS-CoV-2, severe acute respiratory syndrome coronavirus 2; COVID-19, coronavirus disease 2019; SCFAs, short-chain fatty acids; dpi, day post-infection; RT-PCR, reverse transcription polymerase chain reaction; IL, interleukin. ACE2, angiotensin converting enzyme 2; TMPRSS2, transmembrane serine protease 2.


Subject(s)
COVID-19/microbiology , COVID-19/physiopathology , Disease Models, Animal , Gastrointestinal Microbiome , Mesocricetus , Animals , Bacteria/classification , Bacteria/isolation & purification , Bacteria/metabolism , COVID-19/drug therapy , COVID-19/pathology , Cricetinae , Fatty Acids, Volatile/administration & dosage , Fatty Acids, Volatile/metabolism , Humans , Male , SARS-CoV-2/physiology , Severity of Illness Index
4.
Viruses ; 13(12)2021 12 14.
Article in English | MEDLINE | ID: covidwho-1572667

ABSTRACT

Pre-existing comorbidities such as obesity or metabolic diseases can adversely affect the clinical outcome of COVID-19. Chronic metabolic disorders are globally on the rise and often a consequence of an unhealthy diet, referred to as a Western Diet. For the first time in the Syrian hamster model, we demonstrate the detrimental impact of a continuous high-fat high-sugar diet on COVID-19 outcome. We observed increased weight loss and lung pathology, such as exudate, vasculitis, hemorrhage, fibrin, and edema, delayed viral clearance and functional lung recovery, and prolonged viral shedding. This was accompanied by an altered, but not significantly different, systemic IL-10 and IL-6 profile, as well as a dysregulated serum lipid response dominated by polyunsaturated fatty acid-containing phosphatidylethanolamine, partially recapitulating cytokine and lipid responses associated with severe human COVID-19. Our data support the hamster model for testing restrictive or targeted diets and immunomodulatory therapies to mediate the adverse effects of metabolic disease on COVID-19.


Subject(s)
COVID-19 , Diet, High-Fat/adverse effects , Dietary Carbohydrates/adverse effects , Lipid Metabolism , Severity of Illness Index , Animals , COVID-19/pathology , Cricetinae , Cytokines/blood , Disease Models, Animal , Edema , Fibrin , Hemorrhage , Humans , Interleukin-10 , Interleukin-6 , Lipidomics , Lipids/blood , Liver/pathology , Lung/pathology , Male , Mesocricetus , Obesity , SARS-CoV-2 , Sugars , Vasculitis/pathology , Virus Shedding
5.
Viruses ; 13(12)2021 12 03.
Article in English | MEDLINE | ID: covidwho-1555015

ABSTRACT

We have developed a monoclonal antibody (mAb) cocktail (ZRC-3308) comprising of ZRC3308-A7 and ZRC3308-B10 in the ratio 1:1 for COVID-19 treatment. The mAbs were designed to have reduced immune effector functions and increased circulation half-life. mAbs showed good binding affinities to non-competing epitopes on RBD of SARS-CoV-2 spike protein and were found neutralizing SARS-CoV-2 variants B.1, B.1.1.7, B.1.351, B.1.617.2, and B.1.617.2 AY.1 in vitro. The mAb cocktail demonstrated effective prophylactic and therapeutic activity against SARS-CoV-2 infection in Syrian hamsters. The antibody cocktail appears to be a promising candidate for prophylactic use and for therapy in early COVID-19 cases that have not progressed to severe disease.


Subject(s)
Antibodies, Monoclonal, Humanized/immunology , COVID-19/therapy , SARS-CoV-2/immunology , Animals , Antibodies, Monoclonal, Humanized/therapeutic use , Antibodies, Neutralizing/immunology , Antibodies, Neutralizing/therapeutic use , Antibody Affinity , Binding Sites , COVID-19/prevention & control , Cricetinae , Disease Models, Animal , Epitopes , Humans , Immunization, Passive , Mesocricetus , Mutation , SARS-CoV-2/genetics , Spike Glycoprotein, Coronavirus/genetics , Spike Glycoprotein, Coronavirus/immunology
6.
Sci Rep ; 11(1): 21849, 2021 11 08.
Article in English | MEDLINE | ID: covidwho-1505527

ABSTRACT

The huge worldwide demand for vaccines targeting SARS-CoV-2 has necessitated the continued development of novel improved formulations capable of reducing the burden of the COVID-19 pandemic. Herein, we evaluated novel protein subunit vaccine formulations containing a resistin-trimerized spike antigen, SmT1. When combined with sulfated lactosyl archaeol (SLA) archaeosome adjuvant, formulations induced robust antigen-specific humoral and cellular immune responses in mice. Antibodies had strong neutralizing activity, preventing viral spike binding and viral infection. In addition, the formulations were highly efficacious in a hamster challenge model reducing viral load and body weight loss even after a single vaccination. The antigen-specific antibodies generated by our vaccine formulations had stronger neutralizing activity than human convalescent plasma, neutralizing the spike proteins of the B.1.1.7 and B.1.351 variants of concern. As such, our SmT1 antigen along with SLA archaeosome adjuvant comprise a promising platform for the development of efficacious protein subunit vaccine formulations for SARS-CoV-2.


Subject(s)
Adjuvants, Immunologic/chemistry , Antigens, Archaeal/chemistry , COVID-19 Vaccines/therapeutic use , Lipids/chemistry , Animals , Antibodies, Neutralizing/immunology , Antibodies, Viral/immunology , Body Weight , COVID-19/therapy , Chlorocebus aethiops , Cricetinae , Cytokines/metabolism , Female , Humans , Immunity, Cellular , Immunity, Humoral , Immunization, Passive , Mesocricetus , Mice , Mice, Inbred C57BL , Neutralization Tests , Peptides/chemistry , Protein Domains , SARS-CoV-2 , Toll-Like Receptors/immunology , Vero Cells , Viral Load
7.
Nat Neurosci ; 24(11): 1522-1533, 2021 11.
Article in English | MEDLINE | ID: covidwho-1500484

ABSTRACT

Coronavirus disease 2019 (COVID-19) can damage cerebral small vessels and cause neurological symptoms. Here we describe structural changes in cerebral small vessels of patients with COVID-19 and elucidate potential mechanisms underlying the vascular pathology. In brains of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2)-infected individuals and animal models, we found an increased number of empty basement membrane tubes, so-called string vessels representing remnants of lost capillaries. We obtained evidence that brain endothelial cells are infected and that the main protease of SARS-CoV-2 (Mpro) cleaves NEMO, the essential modulator of nuclear factor-κB. By ablating NEMO, Mpro induces the death of human brain endothelial cells and the occurrence of string vessels in mice. Deletion of receptor-interacting protein kinase (RIPK) 3, a mediator of regulated cell death, blocks the vessel rarefaction and disruption of the blood-brain barrier due to NEMO ablation. Importantly, a pharmacological inhibitor of RIPK signaling prevented the Mpro-induced microvascular pathology. Our data suggest RIPK as a potential therapeutic target to treat the neuropathology of COVID-19.


Subject(s)
Blood-Brain Barrier/metabolism , Brain/metabolism , Coronavirus 3C Proteases/metabolism , Intracellular Signaling Peptides and Proteins/metabolism , Microvessels/metabolism , SARS-CoV-2/metabolism , Animals , Blood-Brain Barrier/pathology , Brain/pathology , Chlorocebus aethiops , Coronavirus 3C Proteases/genetics , Cricetinae , Female , Humans , Intracellular Signaling Peptides and Proteins/genetics , Male , Mesocricetus , Mice , Mice, Inbred C57BL , Mice, Knockout , Mice, Transgenic , Microvessels/pathology , SARS-CoV-2/genetics , Vero Cells
8.
J Clin Invest ; 131(20)2021 10 15.
Article in English | MEDLINE | ID: covidwho-1501861

ABSTRACT

The mRNA-1273 vaccine is effective against SARS-CoV-2 and was granted emergency use authorization by the FDA. Clinical studies, however, cannot provide the controlled response to infection and complex immunological insight that are only possible with preclinical studies. Hamsters are the only model that reliably exhibits severe SARS-CoV-2 disease similar to that in hospitalized patients, making them pertinent for vaccine evaluation. We demonstrate that prime or prime-boost administration of mRNA-1273 in hamsters elicited robust neutralizing antibodies, ameliorated weight loss, suppressed SARS-CoV-2 replication in the airways, and better protected against disease at the highest prime-boost dose. Unlike in mice and nonhuman primates, low-level virus replication in mRNA-1273-vaccinated hamsters coincided with an anamnestic response. Single-cell RNA sequencing of lung tissue permitted high-resolution analysis that is not possible in vaccinated humans. mRNA-1273 prevented inflammatory cell infiltration and the reduction of lymphocyte proportions, but enabled antiviral responses conducive to lung homeostasis. Surprisingly, infection triggered transcriptome programs in some types of immune cells from vaccinated hamsters that were shared, albeit attenuated, with mock-vaccinated hamsters. Our results support the use of mRNA-1273 in a 2-dose schedule and provide insight into the potential responses within the lungs of vaccinated humans who are exposed to SARS-CoV-2.


Subject(s)
COVID-19 Vaccines/pharmacology , COVID-19/immunology , COVID-19/prevention & control , Lung/immunology , SARS-CoV-2 , Animals , Antibodies, Neutralizing/biosynthesis , Antibodies, Viral/biosynthesis , COVID-19/virology , COVID-19 Vaccines/administration & dosage , COVID-19 Vaccines/immunology , Disease Models, Animal , Female , Humans , Immunization, Secondary , Lung/pathology , Lung/virology , Lymphocyte Activation , Mesocricetus , SARS-CoV-2/immunology , SARS-CoV-2/physiology , Single-Cell Analysis , Virus Replication
9.
Emerg Microbes Infect ; 10(1): 2016-2029, 2021 Dec.
Article in English | MEDLINE | ID: covidwho-1493580

ABSTRACT

ABSTRACTA COVID-19 vaccine that can give early protection is needed to eliminate the viral spread efficiently. Here, we demonstrate the development of a nanoparticle vaccine candidate, REVC-128, in which multiple trimeric spike ectodomains with glycine (G) at position 614 were multimerized onto a nanoparticle. In-vitro characterization of this vaccine confirms its structural and antigenic integrity. In-vivo immunogenicity evaluation in mice indicates that a single dose of this vaccine induces potent serum neutralizing antibody titre at two weeks post-immunization. This is significantly higher than titre caused by trimeric spike protein without nanoparticle presentation. The comparison of serum binding to spike subunits between animals immunized by a spike with and without nanoparticle presentation indicates that nanoparticle prefers the display of spike RBD (Receptor-Binding Domain) over S2 subunit, likely resulting in a more neutralizing but less cross-reactive antibody response. Moreover, a Syrian golden hamster in-vivo model for the SARS-CoV-2 virus challenge was implemented two weeks post a single dose of REVC-128 immunization. The results showed that vaccination protects hamsters against the SARS-CoV-2 virus challenge with evidence of steady body weight, suppressed viral loads and alleviation of tissue damage for protected animals, compared with ∼10% weight loss, high viral loads and tissue damage in unprotected animals. Furthermore, the data showed that vaccine REVC-128 is thermostable at up to 37°C for at least 4 weeks. These findings, along with a history of safety for protein vaccines, suggest that the REVC-128 is a safe, stable and efficacious single-shot vaccine to give the earliest protection against SARS-CoV-2 infection.


Subject(s)
COVID-19 Vaccines/immunology , COVID-19/prevention & control , Nanoparticles/chemistry , SARS-CoV-2 , Animals , Antibodies, Neutralizing , Antibodies, Viral/blood , Antibody Formation , COVID-19 Vaccines/administration & dosage , Cricetinae , Humans , Immunization , Immunization Schedule , Immunogenicity, Vaccine , Mesocricetus , Mice , Spike Glycoprotein, Coronavirus , Vaccination , Viral Load
10.
Sci Rep ; 11(1): 21259, 2021 10 28.
Article in English | MEDLINE | ID: covidwho-1493217

ABSTRACT

Coronavirus disease 2019 (COVID-19) caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is currently a serious public health concern worldwide. Notably, co-infection with other pathogens may worsen the severity of COVID-19 symptoms and increase fatality. Here, we show that co-infection with influenza A virus (IAV) causes more severe body weight loss and more severe and prolonged pneumonia in SARS-CoV-2-infected hamsters. Each virus can efficiently spread in the lungs without interference by the other. However, in immunohistochemical analyses, SARS-CoV-2 and IAV were not detected at the same sites in the respiratory organs of co-infected hamsters, suggesting that either the two viruses may have different cell tropisms in vivo or each virus may inhibit the infection and/or growth of the other within a cell or adjacent areas in the organs. Furthermore, a significant increase in IL-6 was detected in the sera of hamsters co-infected with SARS-CoV-2 and IAV at 7 and 10 days post-infection, suggesting that IL-6 may be involved in the increased severity of pneumonia. Our results strongly suggest that IAV co-infection with SARS-CoV-2 can have serious health risks and increased caution should be applied in such cases.


Subject(s)
COVID-19/complications , Orthomyxoviridae Infections/complications , Pneumonia, Viral/complications , SARS-CoV-2 , Animals , COVID-19/pathology , COVID-19/virology , Coinfection/pathology , Disease Models, Animal , Female , Humans , Interleukin-6/blood , Lung/diagnostic imaging , Lung/pathology , Mesocricetus , Orthomyxoviridae/pathogenicity , Orthomyxoviridae Infections/pathology , Orthomyxoviridae Infections/virology , Pneumonia, Viral/pathology , Pneumonia, Viral/virology , SARS-CoV-2/pathogenicity , SARS-CoV-2/physiology , Severity of Illness Index , Virus Replication
11.
Nat Commun ; 12(1): 6277, 2021 11 01.
Article in English | MEDLINE | ID: covidwho-1493102

ABSTRACT

Several COVID-19 vaccines have now been deployed to tackle the SARS-CoV-2 pandemic, most of them based on messenger RNA or adenovirus vectors.The duration of protection afforded by these vaccines is unknown, as well as their capacity to protect from emerging new variants. To provide sufficient coverage for the world population, additional strategies need to be tested. The live pediatric measles vaccine (MV) is an attractive approach, given its extensive safety and efficacy history, along with its established large-scale manufacturing capacity. We develop an MV-based SARS-CoV-2 vaccine expressing the prefusion-stabilized, membrane-anchored full-length S antigen, which proves to be efficient at eliciting strong Th1-dominant T-cell responses and high neutralizing antibody titers. In both mouse and golden Syrian hamster models, these responses protect the animals from intranasal infectious challenge. Additionally, the elicited antibodies efficiently neutralize in vitro the three currently circulating variants of SARS-CoV-2.


Subject(s)
COVID-19 Vaccines/immunology , COVID-19/immunology , Genetic Vectors , Immunity , Adenoviridae , Animals , Antibodies, Neutralizing/immunology , Antibodies, Viral/immunology , COVID-19/prevention & control , COVID-19 Vaccines/administration & dosage , Cricetinae , Cytokines , Female , Immunization , Immunization, Secondary , Male , Measles Vaccine/immunology , Mesocricetus , Mice , SARS-CoV-2/genetics , Spike Glycoprotein, Coronavirus/genetics , Spike Glycoprotein, Coronavirus/immunology
12.
Nat Neurosci ; 24(11): 1522-1533, 2021 11.
Article in English | MEDLINE | ID: covidwho-1483143

ABSTRACT

Coronavirus disease 2019 (COVID-19) can damage cerebral small vessels and cause neurological symptoms. Here we describe structural changes in cerebral small vessels of patients with COVID-19 and elucidate potential mechanisms underlying the vascular pathology. In brains of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2)-infected individuals and animal models, we found an increased number of empty basement membrane tubes, so-called string vessels representing remnants of lost capillaries. We obtained evidence that brain endothelial cells are infected and that the main protease of SARS-CoV-2 (Mpro) cleaves NEMO, the essential modulator of nuclear factor-κB. By ablating NEMO, Mpro induces the death of human brain endothelial cells and the occurrence of string vessels in mice. Deletion of receptor-interacting protein kinase (RIPK) 3, a mediator of regulated cell death, blocks the vessel rarefaction and disruption of the blood-brain barrier due to NEMO ablation. Importantly, a pharmacological inhibitor of RIPK signaling prevented the Mpro-induced microvascular pathology. Our data suggest RIPK as a potential therapeutic target to treat the neuropathology of COVID-19.


Subject(s)
Blood-Brain Barrier/metabolism , Brain/metabolism , Coronavirus 3C Proteases/metabolism , Intracellular Signaling Peptides and Proteins/metabolism , Microvessels/metabolism , SARS-CoV-2/metabolism , Animals , Blood-Brain Barrier/pathology , Brain/pathology , Chlorocebus aethiops , Coronavirus 3C Proteases/genetics , Cricetinae , Female , Humans , Intracellular Signaling Peptides and Proteins/genetics , Male , Mesocricetus , Mice , Mice, Inbred C57BL , Mice, Knockout , Mice, Transgenic , Microvessels/pathology , SARS-CoV-2/genetics , Vero Cells
13.
mBio ; 12(5): e0252721, 2021 10 26.
Article in English | MEDLINE | ID: covidwho-1476394

ABSTRACT

Respiratory viruses such as SARS-CoV-2 are transmitted in respiratory droplets and aerosol particles, which are released during talking, breathing, coughing, and sneezing. Noncontact transmission of SARS-CoV-2 has been demonstrated, suggesting transmission via virus carried through the air. Here, we demonstrate that golden Syrian hamsters produce infectious SARS-CoV-2 in aerosol particles prior to and concurrent with the onset of mild clinical signs of disease. The average emission rate in this study was 25 infectious virions/hour on days 1 and 2 postinoculation, with average viral RNA levels 200-fold higher than infectious virus in aerosol particles. The majority of virus was contained within particles <5 µm in size. Thus, we provide direct evidence that, in hamsters, SARS-CoV-2 is an airborne virus. IMPORTANCE SARS-CoV-2 is a respiratory virus and has been isolated from the air near COVID-19 patients. Here, using a hamster model of infection, we demonstrate that SARS-CoV-2 is emitted in aerosol particles prior to and concurrent with the onset of mild disease. Virus is contained primarily within aerosol particles <5 µm in size, which can remain airborne and be inhaled. These findings indicate that SARS-CoV-2 is an airborne virus and support the use of ventilation to reduce SARS-CoV-2 transmission.


Subject(s)
Aerosols , COVID-19/transmission , SARS-CoV-2/pathogenicity , Animals , COVID-19/metabolism , Chlorocebus aethiops , Cricetinae , Mesocricetus , Real-Time Polymerase Chain Reaction , Vero Cells
14.
Nat Commun ; 12(1): 6097, 2021 10 20.
Article in English | MEDLINE | ID: covidwho-1475295

ABSTRACT

Effective treatments against Severe Acute Respiratory Syndrome coronavirus 2 (SARS-CoV-2) are urgently needed. Monoclonal antibodies have shown promising results in patients. Here, we evaluate the in vivo prophylactic and therapeutic effect of COVA1-18, a neutralizing antibody highly potent against the B.1.1.7 isolate. In both prophylactic and therapeutic settings, SARS-CoV-2 remains undetectable in the lungs of treated hACE2 mice. Therapeutic treatment also causes a reduction in viral loads in the lungs of Syrian hamsters. When administered at 10 mg kg-1 one day prior to a high dose SARS-CoV-2 challenge in cynomolgus macaques, COVA1-18 shows very strong antiviral activity in the upper respiratory compartments. Using a mathematical model, we estimate that COVA1-18 reduces viral infectivity by more than 95% in these compartments, preventing lymphopenia and extensive lung lesions. Our findings demonstrate that COVA1-18 has a strong antiviral activity in three preclinical models and could be a valuable candidate for further clinical evaluation.


Subject(s)
Antibodies, Monoclonal/administration & dosage , Antibodies, Neutralizing/administration & dosage , Antiviral Agents/administration & dosage , COVID-19/drug therapy , SARS-CoV-2/immunology , Angiotensin-Converting Enzyme 2/genetics , Animals , Antibodies, Monoclonal/pharmacokinetics , Antiviral Agents/pharmacokinetics , COVID-19/blood , COVID-19/immunology , COVID-19/virology , Disease Models, Animal , Drug Evaluation, Preclinical , Female , Humans , Lung/metabolism , Lung/virology , Macaca fascicularis , Male , Mesocricetus , Mice , Mice, Transgenic , SARS-CoV-2/isolation & purification , Tissue Distribution , Viral Load
15.
PLoS Pathog ; 17(10): e1009542, 2021 10.
Article in English | MEDLINE | ID: covidwho-1468184

ABSTRACT

The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) that causes the disease COVID-19 can lead to serious symptoms, such as severe pneumonia, in the elderly and those with underlying medical conditions. While vaccines are now available, they do not work for everyone and therapeutic drugs are still needed, particularly for treating life-threatening conditions. Here, we showed nasal delivery of a new, unmodified camelid single-domain antibody (VHH), termed K-874A, effectively inhibited SARS-CoV-2 titers in infected lungs of Syrian hamsters without causing weight loss and cytokine induction. In vitro studies demonstrated that K-874A neutralized SARS-CoV-2 in both VeroE6/TMPRSS2 and human lung-derived alveolar organoid cells. Unlike other drug candidates, K-874A blocks viral membrane fusion rather than viral attachment. Cryo-electron microscopy revealed K-874A bound between the receptor binding domain and N-terminal domain of the virus S protein. Further, infected cells treated with K-874A produced fewer virus progeny that were less infective. We propose that direct administration of K-874A to the lung could be a new treatment for preventing the reinfection of amplified virus in COVID-19 patients.


Subject(s)
Antibodies, Viral/administration & dosage , Antiviral Agents/administration & dosage , COVID-19 , Single-Domain Antibodies/administration & dosage , Virus Attachment/drug effects , Administration, Intranasal , Animals , Chlorocebus aethiops , Cricetinae , Disease Models, Animal , Humans , Mesocricetus , SARS-CoV-2 , Spike Glycoprotein, Coronavirus/immunology , Vero Cells
16.
Nat Commun ; 12(1): 5868, 2021 10 07.
Article in English | MEDLINE | ID: covidwho-1462005

ABSTRACT

We investigated ChAdOx1 nCoV-19 (AZD1222) vaccine efficacy against SARS-CoV-2 variants of concern (VOCs) B.1.1.7 and B.1.351 in Syrian hamsters. We previously showed protection against SARS-CoV-2 disease and pneumonia in hamsters vaccinated with a single dose of ChAdOx1 nCoV-19. Here, we observe a 9.5-fold reduction of virus neutralizing antibody titer in vaccinated hamster sera against B.1.351 compared to B.1.1.7. Vaccinated hamsters challenged with B.1.1.7 or B.1.351 do not lose weight compared to control animals. In contrast to control animals, the lungs of vaccinated animals do not show any gross lesions. Minimal to no viral subgenomic RNA (sgRNA) and no infectious virus can be detected in lungs of vaccinated animals. Histopathological evaluation shows extensive pulmonary pathology caused by B.1.1.7 or B.1.351 replication in the control animals, but none in the vaccinated animals. These data demonstrate the effectiveness of the ChAdOx1 nCoV-19 vaccine against clinical disease caused by B.1.1.7 or B.1.351 VOCs.


Subject(s)
COVID-19 Vaccines/immunology , COVID-19/immunology , COVID-19/prevention & control , SARS-CoV-2/immunology , Administration, Intranasal , Amino Acid Substitution , Animals , Antibodies, Neutralizing/immunology , Antibodies, Viral/immunology , COVID-19/virology , Female , Lung/immunology , Lung/pathology , Lung/virology , Mesocricetus , Spike Glycoprotein, Coronavirus/immunology , Vaccination
17.
J Virol Methods ; 299: 114306, 2022 01.
Article in English | MEDLINE | ID: covidwho-1446918

ABSTRACT

Considering the global impact of the coronavirus disease 2019 (COVID-19) pandemic, generating suitable experimental models is imperative. For pre-clinical studies, researchers require animal models displaying pathological features similar to those observed in patients; therefore, establishing animal models for COVID-19 is crucial. The golden Syrian hamster model mimics conditions observed in humans with mild severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection. However, a golden Syrian hamster model of severe infection has not been reported. J2N-k hamsters are utilized as a cardiomyopathy model; therefore, we used cardiomyopathic J2N-k hamsters showing conditions similar to those of severe COVID-19 complicated with cardiovascular diseases, as patients with cardiovascular diseases exhibit a higher risk of morbidity and mortality due to COVID-19 than patients without cardiovascular diseases. Unlike that in golden Syrian hamsters, SARS-CoV-2 infection was lethal in J2N-k hamsters, with a median lethal dose of 104.75 plaque-forming units for the S clade of SARS-CoV-2 (A, GenBank: MW466791.1). High viral titers and viral genomes were detected in the lungs of J2N-k and golden Syrian hamster models harvested 3 days after infection. Pathological features of SARS-CoV-2-associated lung injury were observed in both models. The J2N-k hamster model can aid in developing vaccines or therapeutics against COVID-19.


Subject(s)
COVID-19 , Cardiovascular Diseases , Animals , Cricetinae , Disease Models, Animal , Humans , Mesocricetus , Pandemics , SARS-CoV-2
18.
Comp Med ; 71(5): 398-410, 2021 10 01.
Article in English | MEDLINE | ID: covidwho-1444660

ABSTRACT

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), the cause of coronavirus disease 2019 (COVID-19), rapidly spread across the world in late 2019, leading to a pandemic. While SARS-CoV-2 infections predominately affect the respiratory system, severe infections can lead to renal and cardiac injury and even death. Due to its highly transmissible nature and severe health implications, animal models of SARS-CoV-2 are critical to developing novel therapeutics and preventatives. Syrian hamsters (Mesocricetus auratus) are an ideal animal model of SARS-CoV-2 infections because they recapitulate many aspects of human infections. After inoculation with SARS-CoV-2, hamsters become moribund, lose weight, and show varying degrees of respiratory disease, lethargy, and ruffled fur. Histopathologically, their pulmonary lesions are consistent with human infections including interstitial to broncho-interstitial pneumonia, alveolar hemorrhage and edema, and granulocyte infiltration. Similar to humans, the duration of clinical signs and pulmonary pathology are short lived with rapid recovery by 14 d after infection. Immunocompromised hamsters develop more severe infections and mortality. Preclinical studies in hamsters have shown efficacy of therapeutics, including convalescent serum treatment, and preventatives, including vaccination, in limiting or preventing clinical disease. Although hamster studies have contributed greatly to our understanding of the pathogenesis and progression of disease after SARS-CoV-2 infection, additional studies are required to better characterize the effects of age, sex, and virus variants on clinical outcomes in hamsters. This review aims to describe key findings from studies of hamsters infected with SARS-CoV-2 and to highlight areas that need further investigation.


Subject(s)
COVID-19 , Coronavirus Infections , Animals , COVID-19/therapy , Cricetinae , Disease Models, Animal , Humans , Immunization, Passive , Mesocricetus , Pandemics , SARS-CoV-2
19.
J Virol ; 95(20): e0101021, 2021 09 27.
Article in English | MEDLINE | ID: covidwho-1440800

ABSTRACT

The host response to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is poorly understood due to a lack of an animal model that recapitulates severe human disease. Here, we report a Syrian hamster model that develops progressive lethal pulmonary disease that closely mimics severe coronavirus disease 2019 (COVID-19). We evaluated host responses using a multi-omic, multiorgan approach to define proteome, phosphoproteome, and transcriptome changes. These data revealed both type I and type II interferon-stimulated gene and protein expression along with a progressive increase in chemokines, monocytes, and neutrophil-associated molecules throughout the course of infection that peaked in the later time points correlating with a rapidly developing diffuse alveolar destruction and pneumonia that persisted in the absence of active viral infection. Extrapulmonary proteome and phosphoproteome remodeling was detected in the heart and kidneys following viral infection. Together, our results provide a kinetic overview of multiorgan host responses to severe SARS-CoV-2 infection in vivo. IMPORTANCE The current pandemic caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection has created an urgent need to understand the pathogenesis of this infection. These efforts have been impaired by the lack of animal models that recapitulate severe coronavirus disease 2019 (COVID-19). Here, we report a hamster model that develops severe COVID-19-like disease following infection with human isolates of SARS-CoV-2. To better understand pathogenesis, we evaluated changes in gene transcription and protein expression over the course of infection to provide an integrated multiorgan kinetic analysis of the host response to infection. These data reveal a dynamic innate immune response to infection and corresponding immune pathologies consistent with severe human disease. Altogether, this model will be useful for understanding the pathogenesis of severe COVID-19 and for testing interventions.


Subject(s)
COVID-19/immunology , COVID-19/metabolism , Immunity, Innate , Proteome , Transcriptome , Animals , COVID-19/genetics , COVID-19/virology , Disease Models, Animal , Gene Ontology , Heart/virology , Kidney/metabolism , Kidney/virology , Lung/immunology , Lung/metabolism , Lung/pathology , Lung/virology , Male , Mesocricetus , Myocardium/metabolism , Phosphoproteins/metabolism , Proteomics , SARS-CoV-2/genetics , SARS-CoV-2/physiology , Severity of Illness Index , Viral Load
20.
J Virol ; 95(20): e0059221, 2021 09 27.
Article in English | MEDLINE | ID: covidwho-1440799

ABSTRACT

The current pandemic of coronavirus disease 2019 (COVID-19) caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has led to dramatic economic and health burdens. Although the worldwide SARS-CoV-2 vaccination campaign has begun, exploration of other vaccine candidates is needed due to uncertainties with the current approved vaccines, such as durability of protection, cross-protection against variant strains, and costs of long-term production and storage. In this study, we developed a methyltransferase-defective recombinant vesicular stomatitis virus (mtdVSV)-based SARS-CoV-2 vaccine candidate. We generated mtdVSVs expressing SARS-CoV-2 full-length spike (S) protein, S1, or its receptor-binding domain (RBD). All of these recombinant viruses grew to high titers in mammalian cells despite high attenuation in cell culture. The SARS-CoV-2 S protein and its truncations were highly expressed by the mtdVSV vector. These mtdVSV-based vaccine candidates were completely attenuated in both immunocompetent and immunocompromised mice. Among these constructs, mtdVSV-S induced high levels of SARS-CoV-2-specific neutralizing antibodies (NAbs) and Th1-biased T-cell immune responses in mice. In Syrian golden hamsters, the serum levels of SARS-CoV-2-specific NAbs triggered by mtdVSV-S were higher than the levels of NAbs in convalescent plasma from recovered COVID-19 patients. In addition, hamsters immunized with mtdVSV-S were completely protected against SARS-CoV-2 replication in lung and nasal turbinate tissues, cytokine storm, and lung pathology. Collectively, our data demonstrate that mtdVSV expressing SARS-CoV-2 S protein is a safe and highly efficacious vaccine candidate against SARS-CoV-2 infection. IMPORTANCE Viral mRNA cap methyltransferase (MTase) is essential for mRNA stability, protein translation, and innate immune evasion. Thus, viral mRNA cap MTase activity is an excellent target for development of live attenuated or live vectored vaccine candidates. Here, we developed a panel of MTase-defective recombinant vesicular stomatitis virus (mtdVSV)-based SARS-CoV-2 vaccine candidates expressing full-length S, S1, or several versions of the RBD. These mtdVSV-based vaccine candidates grew to high titers in cell culture and were completely attenuated in both immunocompetent and immunocompromised mice. Among these vaccine candidates, mtdVSV-S induces high levels of SARS-CoV-2-specific neutralizing antibodies (Nabs) and Th1-biased immune responses in mice. Syrian golden hamsters immunized with mtdVSV-S triggered SARS-CoV-2-specific NAbs at higher levels than those in convalescent plasma from recovered COVID-19 patients. Furthermore, hamsters immunized with mtdVSV-S were completely protected against SARS-CoV-2 challenge. Thus, mtdVSV is a safe and highly effective vector to deliver SARS-CoV-2 vaccine.


Subject(s)
COVID-19 Vaccines/immunology , COVID-19/prevention & control , SARS-CoV-2/immunology , Vesicular stomatitis Indiana virus/genetics , Animals , Antibodies, Neutralizing/blood , Antibodies, Viral/blood , Brain/virology , COVID-19/immunology , Cell Line , Cytokine Release Syndrome/prevention & control , DNA-Directed RNA Polymerases/genetics , DNA-Directed RNA Polymerases/metabolism , Humans , Immunogenicity, Vaccine , Lung/immunology , Lung/pathology , Lung/virology , Mesocricetus , Methyltransferases/genetics , Methyltransferases/metabolism , Mice , Protein Domains , Spike Glycoprotein, Coronavirus/chemistry , Spike Glycoprotein, Coronavirus/genetics , Spike Glycoprotein, Coronavirus/immunology , Th1 Cells/immunology , Vaccines, Synthetic/immunology , Vesicular stomatitis Indiana virus/enzymology , Vesicular stomatitis Indiana virus/physiology , Viral Proteins/genetics , Viral Proteins/metabolism , Virus Replication
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