National Nurses United (NNU) and 44 allied unions and organizations, representing over 13 million members and their communities, are joining in coalition to urge the U.S. Centers for Disease Control and Prevention (CDC) to update its Covid-19 guidance to fully reflect the latest scientific evidence regarding SARS-CoV-2 transmission through aerosols that infected people emit when they breathe, speak, cough, sneeze, or sing.