I'm very skeptical that they know with any serious reliability about the amount needed to cause an infection.
1. The incubation period seems to be quite long in many if not most or all cases.
2. I don't think their research--at least the known research into them is that sophisticated, extensive, trustworthy.
3. Frankly, I don't trust the globalist government folks in charge of such things on this score 0.000000000000000000001%.
They do seem to be just a trifle behind the curve as it were.
Just a few years ago they were denying that these things even existed and that if they did they couldn't cause any disease and if they did cause disease it was only in animals..etc etc...
L