SARS-CoV-2 the source of COVID-19 is an airborne virus that can infect people that breath in a quantity of the contaminated aerosol. Aerosolized means that the virus, that is a very small 0.12 microns, is encapsulated in respiratory droplets of various sizes up to 100 microns. Larger droplets fall out of the air and smaller ones, typically less than 10 microns, can stay in the air for long periods (several hours) and cover much larger distances than 6 ft.
As the respiratory fluid encapsulating one or more virus particles is evaporated by dry air, the time and distance it may remain buoyant increases. These aerosols can move around objects, such as plexiglass partitions, by following the current of the air created by the HVAC system, room fans and filters, movement of people, and buoyancy caused by body heat. Seasonal influenza is of similar size and behaves in a similar way. Controlled ventilation is an aerosol removal mechanism.