Stability and Viability of SARS-CoV-2

To the Editor: The letter by van Doremalen et al. (published March 17 at NEJM.org)(1) provides important information on the viability of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2, the virus that causes Covid-19), and the implication that the virus remains viable in aerosols is likely to influence infection-control practices. The authors used a three-jet Collison nebulizer to generate artificial particles that, because of their small size (<5 mu m), remained suspended in aerosols. However, the authors did not provide data to support the choice of particle size or viral inoculum. A closely related coronavirus, SARS-CoV-1, was not detected in air . . .