LAUSR

www.jogh.org • doi: 10.7189/jogh.10.010344 1 June 2020 • Vol. 10 No. 1 • 010344 R ecent epidemiological data from several sources show that transmission of coronavirus disease (COVID-19) is more efficient in cold and dry climate than in warm and humid locations [1,2]. Strong seasonal character of most respiratory viruses also suggests the important role of environment for viral transmission [3]. This is most often interpreted by seasonal indoor crowding and effects of temperature and humidity on stability of viral particles, but we suggest that this effect is by large a consequence of inactivation of the mucosal barrier by dry air in heated indoor spaces.