The virus that causes COVID-19 spreads mainly through the air when a person coughs, sneezes, sings, talks or breathes. Virus particles can drift in the air and be inhaled, especially in crowded places ...
With U.S. Covid-19 cases at very high levels and new vaccines still several weeks away, we asked experts for their advice on when and where to wear a mask. By Ceylan Yeğinsu and Dani Blum It is the ...