The initial advice was all based on the theory that Covid had a droplet based spread: Wear a cloth mask to catch large droplets before they spread. Stay six f

The initial advice was all based on the theory that Covid had a droplet based spread: Wear a cloth mask to catch large droplets before they spread. Stay six feet apart, because large droplets fall to the ground within that distance. Use hand sanitizer and disinfect surfaces droplets might fall on. Put up sneeze guards at registers to protect the cashiers. However, once you know the virus is fully airborne, you can focus on different things, like improving indoor ventilation in public spaces so you are constantly exchanging inside air for outside air. We have HVAC systems that will help recover the ac/heat when you do this.