I always think infection is both quantitative and qualitative. It's more than plus and minus. Asymptomatic infection is way less serious than by heavily infected case.

Li wen Liang, for example, if infected outdoors casually instead of inside with an old d lady already quite infected, perhaps now still alive.

That's also why medical workers face worst threats, people need to understand their worries.

Any kind of cover will make some difference. That's my belief. Unfortunately like so many things in science, we need time