'Immunity Debt' can be a subtle issue -- especially when human selfishness and common ignorance get involved.
A knee replacement surgeon doesn't wear a mask because they're afraid of catching a bad knee.
Does your immune system need a workout? The bad science behind "immunity debt," explained | Salon.com -- [salon.com]
From the link
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But when everyone locked down, a lot of other viruses died, too. Without human reservoirs to bounce to and from, we almost completely extinguished flu viruses in the United States. In fact, one strain of flu, the Yamagata lineage of influenza B viruses, may even be extinct at this point, thanks to COVID prevention measures like masking, closing schools and staying isolated.
And face masks do a great job of concentrating organisms that we breathe in all the time and keep on recycling them. It is therefore most likely that these organisms that are normally expelled harmlessly now concentrated and returned to the lungs to eventually overpower the bodies defenses leading to astma , bronchitis ,colds etc.
Do they or do they stick to the mask?
@FrayedBear depends on the mask. The ones we are used to seeing, the non surgical and cloth masks, are as useful as elephants gonads on an ant. The virus is tiny and the weave in these masks allows some air flow through them, if not you would choke wearing one. That is why it is recommended you only wear the masks once.
There are masks that give total protection. They usually attached to an oxygen supply and an air scrubber device. These work.