I certainly do not know all the answers. I can tell you this: My wife took every precaution she could take; stayed home, wore a mask when she did go out, washed hands religiously, etc. She got it. I did not. While she was staying in I did all the grocery shopping and took care of everything that required going out. We live in the same house, breathe the same air, etc. Why did she get it and I did not? I don't know.

I am/was personally acquainted with two men who died with COVID. One was in his mid-70s and had emphysema. The other was a few years older and had heart problems (don't know the exact diagnosis). I'm not a doctor, but in my opinion the COVID was the "straw that broke the camel's back" in both cases.

I am personally acquainted with others who have had COVID. For some it was terrible. In the hospital, on oxygen, etc. but not on a vent. For others it was a week or so of feeling "yucky" and weak, but nothing severe. That, more or less, describes my wife's experience. Why are some experiences worse than others? I don't know.

Also, some might say that I had it and just didn't have symptoms. Wife and I have both been tested twice. First test she was positive, I was negative. After our two week quarantine we were tested again. Both negative.