This updated in-depth summary (previously released on December 21, 2020) is issued in response to new information that we received about updated definitions of aerosol particles that show that larger respiratory particles (<100 μm) can remain airborne for extended periods, and that in enclosed areas with poor ventilation, these aerosols containing infectious SARS-CoV-2 can spread beyond 6 feet and build up in a room. We apologize for not including this information in the earlier version of this summary.