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.