Tell me if I'm retarded. Generally we think of airborne diseases spreading when a person sneezes or coughs in the vicinity of another person, or infects a surface which another person touches. When a person sneezes, thousands of water droplets with trillions of viruses are suspended in the air, and this flood of viruses can overwhelm a healthy person's immune system, causing them to get sick. We know that viruses can survive several days or more outside of a host. It stands to reason that viruses in the air could spead many miles and survive the journey before coming in contact with another host. The number of viruses will be very small compared to a direct transmission, so the immune system will easily be able to contain the infection. These microtransmissions can build up the immunity of a person over time before they come in contact with a direct transmission, thus slowing the spread of the pandemic. I think it's possible that all of us are being exposed to microtransmissions of coronavirus as we speak, slowly building immunity to the disease. As long as the direct spread of the disease isn't too rapid, we may have sufficient immunity to halt the spread of pandemic. Once a sufficient portion of the population has built immunity via microtralnsmissions, the pandemic slows down and eventually dies off.