COVID-19 is airborne, but the myths of droplets being the primary mode of transmission and of indoor safety while practicing two metre distancing are still pervasive. Covid is primarily transmitted through aerosols which float and become concentrated in indoor spaces, including well after a contagious individual has left the room.
Room scale aerosol transmission can and does occur. Breathing in the aerosols exhaled by Covid positive individuals is the way you are most likely to contract the virus. Masks are still the best personal defence against inhaling Covid laden aerosols.
While any mask is better than none, simple cloth masks and poorly-sealing surgical masks are not effective protections considering the dramatically increased prevalence and transmissibility of the virus.
This table based on the work of bettermasks.its-airborne.org demonstrates the “relative protection against inhaling these virus laden aerosols as you opt for better mask combinations.”
The chart displays the typical amount of time for a non-infected individual to contract Covid from an infected individual for various combinations of mask types.
Because wild strain Covid and Delta have been almost completely replaced by Omicron, we have a version of the chart with just the Omicron times.
Please wear a mask, the best mask you can, to protect yourself and others.