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1.
EuropePMC; 2022.
Preprint in English | EuropePMC | ID: ppcovidwho-336025

ABSTRACT

Vaccines are a cornerstone in COVID-19 pandemic management. Here, we compare immune responses to and preclinical efficacy of the mRNA vaccine BNT162b2, an adenovirus-vectored spike vaccine, and the live-attenuated-virus vaccine candidate sCPD9 after single and double vaccination in Syrian hamsters. All regimens containing sCPD9 showed superior efficacy. The robust immunity elicited by sCPD9 was evident in a wide range of immune parameters after challenge with heterologous SARS-CoV-2 including rapid viral clearance, reduced tissue damage, fast differentiation of pre-plasmablasts, strong systemic and mucosal humoral responses, and rapid recall of memory T cells from lung tissue. Our results demonstrate that use of live-attenuated vaccines may offer advantages over available COVID-19 vaccines, specifically when applied as booster, and may provide a solution for containment of the COVID-19 pandemic.

2.
Mol Ther ; 30(5): 1952-1965, 2022 May 04.
Article in English | MEDLINE | ID: covidwho-1783847

ABSTRACT

For coronavirus disease 2019 (COVID-19), effective and well-understood treatment options are still scarce. Since vaccine efficacy is challenged by novel variants, short-lasting immunity, and vaccine hesitancy, understanding and optimizing therapeutic options remains essential. We aimed at better understanding the effects of two standard-of-care drugs, dexamethasone and anti-severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) antibodies, on infection and host responses. By using two COVID-19 hamster models, pulmonary immune responses were analyzed to characterize effects of single or combinatorial treatments. Pulmonary viral burden was reduced by anti-SARS-CoV-2 antibody treatment and unaltered or increased by dexamethasone alone. Dexamethasone exhibited strong anti-inflammatory effects and prevented fulminant disease in a severe disease model. Combination therapy showed additive benefits with both anti-viral and anti-inflammatory potency. Bulk and single-cell transcriptomic analyses confirmed dampened inflammatory cell recruitment into lungs upon dexamethasone treatment and identified a specifically responsive subpopulation of neutrophils, thereby indicating a potential mechanism of action. Our analyses confirm the anti-inflammatory properties of dexamethasone and suggest possible mechanisms, validate anti-viral effects of anti-SARS-CoV-2 antibody treatment, and reveal synergistic effects of a combination therapy, thus informing more effective COVID-19 therapies.


Subject(s)
COVID-19 , Animals , Anti-Inflammatory Agents/pharmacology , Anti-Inflammatory Agents/therapeutic use , Antibodies, Viral , Antiviral Agents , COVID-19/drug therapy , Cricetinae , Dexamethasone/pharmacology , SARS-CoV-2 , Transcriptome
3.
EuropePMC; 2020.
Preprint in English | EuropePMC | ID: ppcovidwho-322925

ABSTRACT

The COVID-19 pandemic caused by SARS-CoV-2 has precipitated an unprecedented and yet unresolved crisis worldwide. Different mammals are susceptible to SARS-CoV-2;however, no species examined so far develops robust clinical disease that mirrors severe human cases or allows testing of vaccines and drugs under conditions of severe disease. Here, we compare the susceptibility of three dwarf hamster species (Phodopus spp.) to SARS-CoV-2 and introduce the Roborovski dwarf hamster (P. roborovskii) as a highly susceptible COVID-19 model with consistent and fulminant clinical signs. Particularly, this species shows SARS-CoV-2-induced severe acute diffuse alveolar damage and hyaline microthrombi in the lungs, changes described in patients who succumbed to the infection, but so far not reproduced in any experimentally infected animal. We therefore propose the Roborovski dwarf hamster as an ideal model to examine the efficacy and safety of live attenuated vaccine candidates and novel therapeutics, particularly for their use in highly susceptible individuals.

4.
Sci Adv ; 7(49): eabk0172, 2021 Dec 03.
Article in English | MEDLINE | ID: covidwho-1546430

ABSTRACT

Vaccines are instrumental and indispensable in the fight against the COVID-19 pandemic. Several recent SARS-CoV-2 variants are more transmissible and evade infection- or vaccine-induced protection. We constructed live attenuated vaccine candidates by large-scale recoding of the SARS-CoV-2 genome and showed that the lead candidate, designated sCPD9, protects Syrian hamsters from a challenge with ancestral virus. Here, we assessed immunogenicity and protective efficacy of sCPD9 in the Roborovski dwarf hamster, a nontransgenic rodent species that is highly susceptible to SARS-CoV-2 and severe COVID-19­like disease. We show that a single intranasal vaccination with sCPD9 elicited strong cross-neutralizing antibody responses against four current SARS-CoV-2 variants of concern, B.1.1.7 (Alpha), B.1.351 (Beta), B.1.1.28.1 (Gamma), and B.1.617.2 (Delta). The sCPD9 vaccine offered complete protection from COVID-19­like disease caused by the ancestral SARS-CoV-2 variant B.1 and the two variants of concern B.1.1.7 and B.1.351.

5.
Viruses ; 13(11)2021 11 16.
Article in English | MEDLINE | ID: covidwho-1524173

ABSTRACT

With the exception of inactivated vaccines, all SARS-CoV-2 vaccines currently used for clinical application focus on the spike envelope glycoprotein as a virus-specific antigen. Compared to other SARS-CoV-2 genes, mutations in the spike protein gene are more rapidly selected and spread within the population, which carries the risk of impairing the efficacy of spike-based vaccines. It is unclear to what extent the loss of neutralizing antibody epitopes can be compensated by cellular immune responses, and whether the use of other SARS-CoV-2 antigens might cause a more diverse immune response and better long-term protection, particularly in light of the continued evolution towards new SARS-CoV-2 variants. To address this question, we explored immunogenicity and protective effects of adenoviral vectors encoding either the full-length spike protein (S), the nucleocapsid protein (N), the receptor binding domain (RBD) or a hybrid construct of RBD and the membrane protein (M) in a highly susceptible COVID-19 hamster model. All adenoviral vaccines provided life-saving protection against SARS-CoV-2-infection. The most efficient protection was achieved after exposure to full-length spike. However, the nucleocapsid protein, which triggered a robust T-cell response but did not facilitate the formation of neutralizing antibodies, controlled early virus replication efficiently and prevented severe pneumonia. Although the full-length spike protein is an excellent target for vaccines, it does not appear to be the only option for future vaccine design.


Subject(s)
COVID-19 Vaccines/immunology , COVID-19/immunology , Immunity, Cellular , Immunity, Humoral , Immunogenicity, Vaccine , SARS-CoV-2/immunology , Animals , Antibodies, Neutralizing/blood , Antibodies, Viral/blood , Antigens, Viral/immunology , CD4-Positive T-Lymphocytes/immunology , CD8-Positive T-Lymphocytes/immunology , COVID-19/pathology , COVID-19/prevention & control , COVID-19/virology , Coronavirus Nucleocapsid Proteins/genetics , Coronavirus Nucleocapsid Proteins/immunology , Cricetinae , Female , Inflammation , Lung/pathology , Lung/virology , Male , Mice, Inbred C57BL , Phosphoproteins/genetics , Phosphoproteins/immunology , SARS-CoV-2/physiology , Spike Glycoprotein, Coronavirus/chemistry , Spike Glycoprotein, Coronavirus/genetics , Spike Glycoprotein, Coronavirus/immunology , Viral Matrix Proteins/genetics , Viral Matrix Proteins/immunology
6.
Cell Rep ; 36(5): 109493, 2021 08 03.
Article in English | MEDLINE | ID: covidwho-1328703

ABSTRACT

Safe and effective vaccines are urgently needed to stop the pandemic caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). We construct a series of live attenuated vaccine candidates by large-scale recoding of the SARS-CoV-2 genome and assess their safety and efficacy in Syrian hamsters. Animals were vaccinated with a single dose of the respective recoded virus and challenged 21 days later. Two of the tested viruses do not cause clinical symptoms but are highly immunogenic and induce strong protective immunity. Attenuated viruses replicate efficiently in the upper but not in the lower airways, causing only mild pulmonary histopathology. After challenge, hamsters develop no signs of disease and rapidly clear challenge virus: at no time could infectious virus be recovered from the lungs of infected animals. The ease with which attenuated virus candidates can be produced and administered favors their further development as vaccines to combat the ongoing pandemic.


Subject(s)
COVID-19 Vaccines , COVID-19/immunology , COVID-19/prevention & control , Respiratory System/pathology , Respiratory System/virology , SARS-CoV-2/genetics , SARS-CoV-2/immunology , Animals , Chlorocebus aethiops , Gene Editing , Genome, Viral , Humans , Immunity , Mesocricetus , Mutation , Pandemics/prevention & control , Vaccines, Attenuated , Vero Cells , Virus Replication
8.
Cell Rep ; 33(10): 108488, 2020 12 08.
Article in English | MEDLINE | ID: covidwho-938810

ABSTRACT

The coronavirus disease 2019 (COVID-19) pandemic caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has precipitated an unprecedented and yet-unresolved health crisis worldwide. Different mammals are susceptible to SARS-CoV-2; however, few species examined so far develop robust clinical disease that mirrors severe human cases or allows testing of vaccines and drugs under conditions of severe disease. Here, we compare the susceptibilities of three dwarf hamster species (Phodopus spp.) to SARS-CoV-2 and introduce the Roborovski dwarf hamster (P. roborovskii) as a highly susceptible COVID-19 model with consistent and fulminant clinical signs. Particularly, only this species shows SARS-CoV-2-induced severe acute diffuse alveolar damage and hyaline microthrombi in the lungs, changes described in patients who succumbed to the infection but not reproduced in any experimentally infected animal. Based on our findings, we propose the Roborovski dwarf hamster as a valuable model to examine the efficacy and safety of vaccine candidates and therapeutics, particularly for use in highly susceptible individuals.


Subject(s)
COVID-19/virology , Disease Models, Animal , Lung/virology , Phodopus/virology , SARS-CoV-2 , Angiotensin-Converting Enzyme 2/genetics , Animals , COVID-19/pathology , COVID-19/physiopathology , Lung/pathology , Lung/physiopathology , Pulmonary Alveoli/physiopathology , Pulmonary Alveoli/virology , SARS-CoV-2/genetics
9.
Cell ; 183(4): 1058-1069.e19, 2020 11 12.
Article in English | MEDLINE | ID: covidwho-785287

ABSTRACT

The emergence of SARS-CoV-2 led to pandemic spread of coronavirus disease 2019 (COVID-19), manifesting with respiratory symptoms and multi-organ dysfunction. Detailed characterization of virus-neutralizing antibodies and target epitopes is needed to understand COVID-19 pathophysiology and guide immunization strategies. Among 598 human monoclonal antibodies (mAbs) from 10 COVID-19 patients, we identified 40 strongly neutralizing mAbs. The most potent mAb, CV07-209, neutralized authentic SARS-CoV-2 with an IC50 value of 3.1 ng/mL. Crystal structures of two mAbs in complex with the SARS-CoV-2 receptor-binding domain at 2.55 and 2.70 Å revealed a direct block of ACE2 attachment. Interestingly, some of the near-germline SARS-CoV-2-neutralizing mAbs reacted with mammalian self-antigens. Prophylactic and therapeutic application of CV07-209 protected hamsters from SARS-CoV-2 infection, weight loss, and lung pathology. Our results show that non-self-reactive virus-neutralizing mAbs elicited during SARS-CoV-2 infection are a promising therapeutic strategy.


Subject(s)
Antibodies, Monoclonal/immunology , Antibodies, Viral/immunology , Betacoronavirus/metabolism , Coronavirus Infections/pathology , Pneumonia, Viral/pathology , Angiotensin-Converting Enzyme 2 , Animals , Antibodies, Monoclonal/therapeutic use , Antibodies, Neutralizing/immunology , Antibodies, Viral/therapeutic use , Antigen-Antibody Reactions , Betacoronavirus/immunology , Betacoronavirus/pathogenicity , Binding Sites , COVID-19 , Coronavirus Infections/drug therapy , Coronavirus Infections/virology , Cricetinae , Crystallography, X-Ray , Disease Models, Animal , Humans , Kinetics , Lung/immunology , Lung/metabolism , Lung/pathology , Mice , Mice, Inbred C57BL , Molecular Dynamics Simulation , Pandemics , Peptidyl-Dipeptidase A/chemistry , Peptidyl-Dipeptidase A/metabolism , Pneumonia, Viral/drug therapy , Pneumonia, Viral/virology , Protein Binding , SARS-CoV-2 , Spike Glycoprotein, Coronavirus/chemistry , Spike Glycoprotein, Coronavirus/immunology , Spike Glycoprotein, Coronavirus/metabolism
10.
Transbound Emerg Dis ; 68(3): 1075-1079, 2021 May.
Article in English | MEDLINE | ID: covidwho-781034

ABSTRACT

The SARS-CoV-2 pandemic has caused a yet unresolved global crisis. Effective medical intervention by vaccination or therapy seems to be the only possibility to control the pandemic. In this context, animal models are an indispensable tool for basic and applied research to combat SARS-CoV-2 infection. Here, we established a SARS-CoV-2 infection model in Chinese hamsters suitable for studying pathogenesis of the disease as well as pre-clinical testing of vaccines and therapies. This species of hamster is susceptible to SARS-CoV-2 infection as demonstrated by robust virus replication in the upper and lower respiratory tract accompanied by bronchitis and pneumonia as well as significant body weight loss following infection. The Chinese hamster features advantages compared to the Syrian hamster model, including more pronounced clinical symptoms, its small size, well-characterized genome, transcriptome and translatome data and availability of molecular tools.


Subject(s)
COVID-19/veterinary , Disease Models, Animal , SARS-CoV-2 , Animals , COVID-19/pathology , Cricetinae , Cricetulus , Disease Susceptibility/pathology , Disease Susceptibility/veterinary , Humans , Lung/pathology , Lung/virology , Virus Replication
11.
Viruses ; 12(7):779, 2020.
Article | WHO COVID | ID: covidwho-650369

ABSTRACT

In late 2019, an outbreak of a severe respiratory disease caused by an emerging coronavirus, SARS-CoV-2, resulted in high morbidity and mortality in infected humans. Complete understanding of COVID-19, the multi-faceted disease caused by SARS-CoV-2, requires suitable small animal models, as does the development and evaluation of vaccines and antivirals. Since age-dependent differences of COVID-19 were identified in humans, we compared the course of SARS-CoV-2 infection in young and aged Syrian hamsters. We show that virus replication in the upper and lower respiratory tract was independent of the age of the animals. However, older hamsters exhibited more pronounced and consistent weight loss. In situ hybridization in the lungs identified viral RNA in bronchial epithelium, alveolar epithelial cells type I and II, and macrophages. Histopathology revealed clear age-dependent differences, with young hamsters launching earlier and stronger immune cell influx than aged hamsters. The latter developed conspicuous alveolar and perivascular edema, indicating vascular leakage. In contrast, we observed rapid lung recovery at day 14 after infection only in young hamsters. We propose that comparative assessment in young versus aged hamsters of SARS-CoV-2 vaccines and treatments may yield valuable information, as this small-animal model appears to mirror age-dependent differences in human patients.

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