[DanBC]

> And then what?

They touch their mouth, or eyes, or nose.

> How does the virus get from their face into the lungs in enough quantity to infect them?

They're already infected. I don't understand the question. Are you asking how the virus replicates? It's a strand of RNA that takes over human cell replication. It binds to ACE2, which is how it targets lungs. https://blogs.plos.org/dnascience/2020/02/20/covid-19-vaccin...

People touch their face all day everyday, even when they've been told not to. Even when they're telling other people to stop doing it. https://twitter.com/Kojoanan/status/1235275598697771011

It's unusual for people in public places to be coughed on. I can't think of it happening to me in the past 5 years.

Healthcare professionals wear masks (and goggles, and protective clothing, and sometimes gloves) because their work involves close contact with ill people who are coughing over them.