[ummonk]

The consensus and official line amongst epidemiologists (and the health organizations and media that relayed this official line to the public) was that COVID was only transmitted by droplet transmission i.e. droplets that fall to the ground within several feet (hence the 6 feet / 2 meters social distancing rule) and don't float around in the air. This was despite obvious evidence of outbreaks that could have only occurred via ventilation systems or the virus floating around in the air in an elevator.

Here's an article going over the issue and what convinced them to change their mind: https://www.wired.com/story/the-teeny-tiny-scientific-screwu...

It turned out they were wrong not just about COVID, but a whole host of other diseases, based on erroneous criteria about what sized droplets could float in the air. Ironically, doctors from centuries ago with their theories of "miasma" / bad air would have been closer to the truth.