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2.
Nature ; 586(7830): 583-588, 2020 10.
Article in English | MEDLINE | ID: covidwho-690836

ABSTRACT

A safe and effective vaccine for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) may be required to end the coronavirus disease 2019 (COVID-19) pandemic1-8. For global deployment and pandemic control, a vaccine that requires only a single immunization would be optimal. Here we show the immunogenicity and protective efficacy of a single dose of adenovirus serotype 26 (Ad26) vector-based vaccines expressing the SARS-CoV-2 spike (S) protein in non-human primates. Fifty-two rhesus macaques (Macaca mulatta) were immunized with Ad26 vectors that encoded S variants or sham control, and then challenged with SARS-CoV-2 by the intranasal and intratracheal routes9,10. The optimal Ad26 vaccine induced robust neutralizing antibody responses and provided complete or near-complete protection in bronchoalveolar lavage and nasal swabs after SARS-CoV-2 challenge. Titres of vaccine-elicited neutralizing antibodies correlated with protective efficacy, suggesting an immune correlate of protection. These data demonstrate robust single-shot vaccine protection against SARS-CoV-2 in non-human primates. The optimal Ad26 vector-based vaccine for SARS-CoV-2, termed Ad26.COV2.S, is currently being evaluated in clinical trials.


Subject(s)
Betacoronavirus/immunology , Coronavirus Infections/immunology , Coronavirus Infections/prevention & control , Macaca mulatta , Pandemics/prevention & control , Pneumonia, Viral/immunology , Pneumonia, Viral/prevention & control , Viral Vaccines/administration & dosage , Viral Vaccines/immunology , Animals , COVID-19 , COVID-19 Vaccines , Disease Models, Animal , Female , Immunity, Cellular , Immunity, Humoral , Macaca mulatta/immunology , Macaca mulatta/virology , Male , SARS-CoV-2 , Vaccination , Viral Load
3.
Science ; 369(6505): 812-817, 2020 08 14.
Article in English | MEDLINE | ID: covidwho-327276

ABSTRACT

An understanding of protective immunity to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is critical for vaccine and public health strategies aimed at ending the global coronavirus disease 2019 (COVID-19) pandemic. A key unanswered question is whether infection with SARS-CoV-2 results in protective immunity against reexposure. We developed a rhesus macaque model of SARS-CoV-2 infection and observed that macaques had high viral loads in the upper and lower respiratory tract, humoral and cellular immune responses, and pathologic evidence of viral pneumonia. After the initial viral clearance, animals were rechallenged with SARS-CoV-2 and showed 5 log10 reductions in median viral loads in bronchoalveolar lavage and nasal mucosa compared with after the primary infection. Anamnestic immune responses after rechallenge suggested that protection was mediated by immunologic control. These data show that SARS-CoV-2 infection induced protective immunity against reexposure in nonhuman primates.


Subject(s)
Betacoronavirus , Coronavirus Infections/immunology , Pneumonia, Viral/immunology , Animals , Antibodies, Neutralizing/blood , Antibodies, Neutralizing/immunology , Antibodies, Viral/blood , Antibodies, Viral/immunology , Betacoronavirus/immunology , Betacoronavirus/physiology , Bronchoalveolar Lavage Fluid/virology , COVID-19 , Coronavirus Infections/pathology , Coronavirus Infections/virology , Disease Models, Animal , Female , Immunity, Cellular , Immunity, Humoral , Immunologic Memory , Lung/immunology , Lung/pathology , Lung/virology , Lung Diseases, Interstitial/immunology , Lung Diseases, Interstitial/pathology , Lung Diseases, Interstitial/virology , Macaca mulatta , Male , Nasal Mucosa/virology , Pandemics , Pneumonia, Viral/pathology , Pneumonia, Viral/virology , Recurrence , SARS-CoV-2 , Spike Glycoprotein, Coronavirus/immunology , Viral Load , Virus Replication
4.
Science ; 369(6505): 806-811, 2020 08 14.
Article in English | MEDLINE | ID: covidwho-326877

ABSTRACT

The global coronavirus disease 2019 (COVID-19) pandemic caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has made the development of a vaccine a top biomedical priority. In this study, we developed a series of DNA vaccine candidates expressing different forms of the SARS-CoV-2 spike (S) protein and evaluated them in 35 rhesus macaques. Vaccinated animals developed humoral and cellular immune responses, including neutralizing antibody titers at levels comparable to those found in convalescent humans and macaques infected with SARS-CoV-2. After vaccination, all animals were challenged with SARS-CoV-2, and the vaccine encoding the full-length S protein resulted in >3.1 and >3.7 log10 reductions in median viral loads in bronchoalveolar lavage and nasal mucosa, respectively, as compared with viral loads in sham controls. Vaccine-elicited neutralizing antibody titers correlated with protective efficacy, suggesting an immune correlate of protection. These data demonstrate vaccine protection against SARS-CoV-2 in nonhuman primates.


Subject(s)
Betacoronavirus/immunology , Coronavirus Infections/prevention & control , Pandemics/prevention & control , Pneumonia, Viral/prevention & control , Spike Glycoprotein, Coronavirus/immunology , Vaccines, DNA/immunology , Viral Vaccines/immunology , Adjuvants, Immunologic , Animals , Antibodies, Neutralizing/blood , Antibodies, Neutralizing/immunology , Antibodies, Viral/blood , Antibodies, Viral/immunology , Betacoronavirus/physiology , Bronchoalveolar Lavage Fluid/virology , COVID-19 , COVID-19 Vaccines , Coronavirus Infections/immunology , Coronavirus Infections/virology , Disease Models, Animal , Female , Humans , Immunity, Cellular , Immunity, Humoral , Immunization, Secondary , Immunogenicity, Vaccine , Immunologic Memory , Macaca mulatta , Male , Mutant Proteins/chemistry , Mutant Proteins/immunology , Nasal Mucosa/virology , Pneumonia, Viral/immunology , Pneumonia, Viral/virology , Protein Domains , SARS-CoV-2 , Spike Glycoprotein, Coronavirus/chemistry , Spike Glycoprotein, Coronavirus/genetics , Vaccination , Vaccines, DNA/administration & dosage , Viral Load , Viral Vaccines/administration & dosage
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