biostudies-literatureHawks SAVT | Institute for Critical Technologies and Applied Science, Virginia TechCenter for Emerging, Zoonotic, and Arthropod-borne PathogensHHS | NIH | National Institute of Neurological Disorders and Stroke (NINDS)HHS | NIH | National Institute of Neurological Disorders and StrokeNINDS NIH HHSCenter for Emerging, Zoonotic, and Arthropod-borne Pathogens (Virginia Tech)VT | Institute for Critical Technologies and Applied Science, Virginia Tech (ICTAS)e0252721https://www.ebi.ac.uk/biostudies/studies/S-EPMC8524342biostudies-literatureUnknown12(5)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. <b>IMPORTANCE</b> 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.mBioInfectious SARS-CoV-2 Is Emitted in Aerosol Particles.PMC8524342R01 NS124204R01NS124204Hawks SAPan JMarr LCKuchinsky SCDuggal NKPrussin AJfalseInfectious SARS-CoV-2 Is Emitted in Aerosol Particles.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. <b>IMPORTANCE</b> 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.2021-01-01T00:00:00Z2021 Oct2026-07-09T11:50:47.603Z2026-07-09T11:00:52.676ZS-EPMC85243423466309910.1128/mBio.02527-21