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1.
2021.
Preprint in English | Other preprints | ID: ppcovidwho-294709

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 observed 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 did not lose weight compared to control animals. In contrast to control animals, the lungs of vaccinated animals did not show any gross lesions. Minimal to no viral subgenomic RNA (sgRNA) and no infectious virus was detected in lungs of vaccinated animals. Histopathological evaluation showed 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.

2.
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
3.
Sci Transl Med ; 13(607)2021 08 18.
Article in English | MEDLINE | ID: covidwho-1329033

ABSTRACT

ChAdOx1 nCoV-19/AZD1222 is an approved adenovirus-based vaccine for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) currently being deployed globally. Previous studies in rhesus macaques revealed that intramuscular vaccination with ChAdOx1 nCoV-19/AZD1222 provided protection against pneumonia but did not reduce shedding of SARS-CoV-2 from the upper respiratory tract. Here, we investigated whether intranasally administered ChAdOx1 nCoV-19 reduces detection of virus in nasal swabs after challenging vaccinated macaques and hamsters with SARS-CoV-2 carrying a D614G mutation in the spike protein. Viral loads in swabs obtained from intranasally vaccinated hamsters were decreased compared to control hamsters, and no viral RNA or infectious virus was found in lung tissue after a direct challenge or after direct contact with infected hamsters. Intranasal vaccination of rhesus macaques resulted in reduced virus concentrations in nasal swabs and a reduction in viral loads in bronchoalveolar lavage and lower respiratory tract tissue. Intranasal vaccination with ChAdOx1 nCoV-19/AZD1222 reduced virus concentrations in nasal swabs in two different SARS-CoV-2 animal models, warranting further investigation as a potential vaccination route for COVID-19 vaccines.


Subject(s)
COVID-19 , SARS-CoV-2 , Animals , COVID-19 Vaccines , Cricetinae , Macaca mulatta , Vaccination , Virus Shedding
4.
Nat Commun ; 12(1): 2295, 2021 04 16.
Article in English | MEDLINE | ID: covidwho-1189225

ABSTRACT

The COVID-19 pandemic progresses unabated in many regions of the world. An effective antiviral against SARS-CoV-2 that could be administered orally for use following high-risk exposure would be of substantial benefit in controlling the COVID-19 pandemic. Herein, we show that MK-4482, an orally administered nucleoside analog, inhibits SARS-CoV-2 replication in the Syrian hamster model. The inhibitory effect of MK-4482 on SARS-CoV-2 replication is observed in animals when the drug is administered either beginning 12 h before or 12 h following infection in a high-risk exposure model. These data support the potential utility of MK-4482 to control SARS-CoV-2 infection in humans following high-risk exposure as well as for treatment of COVID-19 patients.


Subject(s)
Antiviral Agents/administration & dosage , COVID-19/drug therapy , Cytidine/analogs & derivatives , Hydroxylamines/administration & dosage , SARS-CoV-2/drug effects , Virus Replication/drug effects , Administration, Oral , Animals , COVID-19/virology , Chlorocebus aethiops , Cytidine/administration & dosage , Disease Models, Animal , Humans , Mesocricetus , SARS-CoV-2/isolation & purification , SARS-CoV-2/physiology , Vero Cells
6.
Cell ; 183(7): 1901-1912.e9, 2020 12 23.
Article in English | MEDLINE | ID: covidwho-950119

ABSTRACT

Long-term severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) shedding was observed from the upper respiratory tract of a female immunocompromised individual with chronic lymphocytic leukemia and acquired hypogammaglobulinemia. Shedding of infectious SARS-CoV-2 was observed up to 70 days, and of genomic and subgenomic RNA up to 105 days, after initial diagnosis. The infection was not cleared after the first treatment with convalescent plasma, suggesting a limited effect on SARS-CoV-2 in the upper respiratory tract of this individual. Several weeks after a second convalescent plasma transfusion, SARS-CoV-2 RNA was no longer detected. We observed marked within-host genomic evolution of SARS-CoV-2 with continuous turnover of dominant viral variants. However, replication kinetics in Vero E6 cells and primary human alveolar epithelial tissues were not affected. Our data indicate that certain immunocompromised individuals may shed infectious virus longer than previously recognized. Detection of subgenomic RNA is recommended in persistently SARS-CoV-2-positive individuals as a proxy for shedding of infectious virus.


Subject(s)
COVID-19/immunology , Common Variable Immunodeficiency/immunology , Leukemia, Lymphocytic, Chronic, B-Cell/immunology , SARS-CoV-2/isolation & purification , Aged , Antibodies, Viral/blood , Antibodies, Viral/immunology , COVID-19/complications , COVID-19/virology , Common Variable Immunodeficiency/blood , Common Variable Immunodeficiency/complications , Common Variable Immunodeficiency/virology , Female , Humans , Leukemia, Lymphocytic, Chronic, B-Cell/blood , Leukemia, Lymphocytic, Chronic, B-Cell/complications , Leukemia, Lymphocytic, Chronic, B-Cell/virology , Respiratory Tract Infections/blood , Respiratory Tract Infections/complications , Respiratory Tract Infections/immunology , Respiratory Tract Infections/virology , SARS-CoV-2/immunology , SARS-CoV-2/pathogenicity
7.
Nature ; 585(7824): 273-276, 2020 09.
Article in English | MEDLINE | ID: covidwho-592386

ABSTRACT

Effective therapies to treat coronavirus disease 2019 (COVID-19) are urgently needed. While many investigational, approved, and repurposed drugs have been suggested as potential treatments, preclinical data from animal models can guide the search for effective treatments by ruling out those that lack efficacy in vivo. Remdesivir (GS-5734) is a nucleotide analogue prodrug with broad antiviral activity1,2 that is currently being investigated in COVID-19 clinical trials and recently received Emergency Use Authorization from the US Food and Drug Administration3,4. In animal models, remdesivir was effective against infection with Middle East respiratory syndrome coronavirus (MERS-CoV) and severe acute respiratory syndrome coronavirus (SARS-CoV)2,5,6. In vitro, remdesivir inhibited replication of SARS-CoV-27,8. Here we investigate the efficacy of remdesivir in a rhesus macaque model of SARS-CoV-2 infection9. Unlike vehicle-treated animals, macaques treated with remdesivir did not show signs of respiratory disease; they also showed reduced pulmonary infiltrates on radiographs and reduced virus titres in bronchoalveolar lavages twelve hours after the first dose. Virus shedding from the upper respiratory tract was not reduced by remdesivir treatment. At necropsy, remdesivir-treated animals had lower lung viral loads and reduced lung damage. Thus, treatment with remdesivir initiated early during infection had a clinical benefit in rhesus macaques infected with SARS-CoV-2. Although the rhesus macaque model does not represent the severe disease observed in some patients with COVID-19, our data support the early initiation of remdesivir treatment in patients with COVID-19 to prevent progression to pneumonia.


Subject(s)
Adenosine Monophosphate/analogs & derivatives , Alanine/analogs & derivatives , Betacoronavirus/drug effects , Coronavirus Infections/drug therapy , Coronavirus Infections/virology , Disease Models, Animal , Macaca mulatta/virology , Pneumonia, Viral/prevention & control , Adenosine Monophosphate/pharmacokinetics , Adenosine Monophosphate/pharmacology , Adenosine Monophosphate/therapeutic use , Alanine/pharmacokinetics , Alanine/pharmacology , Alanine/therapeutic use , Animals , Betacoronavirus/genetics , Betacoronavirus/pathogenicity , Bronchoalveolar Lavage Fluid/virology , COVID-19 , Coronavirus Infections/pathology , Coronavirus Infections/physiopathology , DNA Mutational Analysis , Disease Progression , Drug Resistance, Viral , Female , Lung/drug effects , Lung/pathology , Lung/physiopathology , Lung/virology , Male , Pandemics , Pneumonia, Viral/drug therapy , Pneumonia, Viral/pathology , Pneumonia, Viral/physiopathology , Pneumonia, Viral/virology , SARS-CoV-2 , Secondary Prevention , Time Factors , Viral Load/drug effects , Virus Replication/drug effects , Virus Shedding/drug effects
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