Persistence of Severe Acute Respiratory Syndrome Coronavirus 2 in Aerosol Suspensions

Abstract

We aerosolized severe acute respiratory syndrome coronavirus 2 and determined that its dynamic aerosol efficiency surpassed those of severe acute respiratory syndrome coronavirus and Middle East respiratory syndrome. Although we performed experiment only once across several laboratories, our findings suggest retained infectivity and virion integrity for up to 16 hours in respirable-sized aerosols.

Keywords: 2019 novel coronavirus disease; COVID-19; MERS-CoV; Middle East respiratory syndrome coronavirus; SARS-CoV; SARS-CoV-2; aerosol; coronavirus diseases; respiratory diseases; severe acute respiratory syndrome coronavirus; severe acute respiratory syndrome coronavirus 2; viruses; zoonoses.

Figure 1

Aerosol efficiency of MERS-CoV, SARS-CoV and SARS-CoV-2 at different sites. Graph shows the spray factor (i.e., ratio of nebulizer concentration to aerosol concentration) for MERS-CoV (red), SARS-CoV (blue), and SARS-CoV2 (green). Aerosols were performed at 4 sites and with different nebulizers. AS, Aerogen Solo nebulizer; C3, Collison 3-jet nebulizer; C6, Collison 6-jet nebulizer; MERS-Cov, Middle East respiratory syndrome coronavirus; S1, Tulane University, New Orleans, LA, USA; S2, National Institutes of Health Integrated Research Facility, Fort Detrick, MD, USA; S3, US Army Medical Institute for Infectious Diseases, Fort Detrick, MD, USA; S4, University of Pittsburgh, Pittsburgh, PA, USA; SARS-CoV, severe acute respiratory syndrome coronavirus; SARS-CoV-2, severe acute respiratory syndrome coronavirus 2.

Figure 2

Decay curves of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) in aerosol suspension. A) Aerosol concentration of infectious SARS-CoV-2 as measured by plaque assay found in impinger samples collected at 5 time points of increased aging in aerosol suspension. B) Corresponding aerosol concentration of SARS-CoV-2 in time-matched impinger samples as a function of viral genome copies as measured by reverse transcription quantitative PCR. Both time point virus estimates were graphed, and nonlinear least-squares regression analysis single-order decay with no outlier detection was performed, resulting in a poor curve fit by either method of viral quantitation resulting from number and lack of iterative samples in this analysis.