The ability of generating recombinant viruses using reverse genetics approaches represents a powerful tool to answer important questions in the biology of viral infections. Nonetheless, a feature of SARS-CoV-2 that is unique among known betacoronaviruses is the presence of a furin cleavage site in the viral spike (S) glycoprotein, a characteristic known to increase pathogenicity and transmissibility in other viruses ( 10). Like that of SARS-CoV, the SARS-CoV-2 genome is approximately 30,000 bases in length. These were severe acute respiratory syndrome CoV (SARS-CoV) in 2002 and Middle East respiratory syndrome CoV (MERS-CoV) in 2012 ( 9). However, two previous CoVs have been associated with severe illnesses and resulted in significant morbidity and mortality in humans. Food and Drug Administration (FDA)-approved prophylactics (vaccines) or specific therapeutics (antivirals) available for the prevention and treatment, respectively, of SARS-CoV-2-associated COVID-19 disease.Д¬oVs are enveloped, single-stranded, positive-sense RNA viruses belonging to the Nidovirales order and responsible for causing seasonal mild respiratory illness in humans (e.g., 229E, NL63, OC43, HKU1). The unprecedented human health and socioeconomic impact of COVID-19 rivals only that of the вЂњSpanish fluвЂќ pandemic, which occurred almost 100вЂ‰years ago ( 4, вЂ“ 8). Since then, severe acute respiratory syndrome CoV-2 (SARS-CoV-2), the ethological agent responsible for CoV disease 2019 (COVID-19), has been detected in 216 countries, areas, or territories, and it has been responsible for over 11,125,245 human cases and 528,204 deaths ( ). In December 2019, a previously unknown coronavirus (CoV) was isolated in Wuhan (China) from a patient with respiratory disease who had possible contact with wild animals ( 1, вЂ“ 3). This SARS-CoV-2 BAC-based reverse genetics will facilitate studies addressing several important questions in the biology of SARS-CoV-2, as well as the identification of antivirals and development of vaccines for the treatment of SARS-CoV-2 infection and associated COVID-19 disease.

This is, to our knowledge, the first BAC-based reverse genetics system for the generation of infectious rSARS-CoV-2 that displays features in vivo similar to those of a natural viral isolate. Likewise, rSARS-CoV-2 showed levels of replication similar to those of the natural isolate in nasal turbinates and lungs of infected golden Syrian hamsters. Importantly, BAC-derived rSARS-CoV-2 exhibited growth properties and plaque sizes in cultured cells comparable to those of the natural SARS-CoV-2 isolate.

Recombinant SARS-CoV-2 (rSARS-CoV-2) was readily rescued by transfection of the BAC into Vero E6 cells.

To contribute to these efforts, we have developed an infectious cDNA clone of the SARS-CoV-2 USA-WA1/2020 strain based on the use of a bacterial artificial chromosome (BAC). Food and Drug Administration (FDA)-approved vaccines or therapeutics available for the prevention or treatment of SARS-CoV-2 infection and/or associated COVID-19 disease, which has triggered a large influx of scientific efforts to develop countermeasures to control SARS-CoV-2 spread. A previously unknown coronavirus, severe acute respiratory syndrome CoV-2 (SARS-CoV-2), has been identified as the causative agent of COVID-19. Infectious coronavirus (CoV) disease 2019 (COVID-19) emerged in the city of Wuhan (China) in December 2019, causing a pandemic that has dramatically impacted public health and socioeconomic activities worldwide.

Data rescue 4 reverse clone