Note, particularly, this paragraph under
"Third, the 99/95/100 classification system only applies to particulates down to 2.5 micrometers in size. While this sounds exceedingly small – and it is – it’s not actually as small as it’s possible for particulate to be".
From the second paragraph in the SOTT article reference by this thread:
"The main transmission path is long-residence-time aerosol particles (< 2.5 μm), which are too fine to be blocked, and the minimum-infective-dose is smaller than one aerosol particle."
Although masks generally filter out larger droplets just fine, the aerosol droplet that may contain this virus can be as small as 1 μm in size, far too small to be stopped by any standard masks generally available to the public.
note: 2.5 micrometers = 2.5 μm
The obvious conclusion must be that even the best N95, N99, and N100 respirators are NOT designed to filter out the long-residence-time aerosol particles of SARS-CoV-2 virus.
I have learned that they have not determined how much virus taken in is sufficient to causes an infection. Certain low levels may not cause symptoms or result in an infection. That kind of science needs to be done. It may be that constant exposure to low levels may cause the effect of a vaccine. As your immune system fights these low level infections, it develops an immunity. That would be a good thing.