I'd think that spending an hour most days in a space with a hundred people would mean getting sick more frequently than when I just sat at home working all day.
Adding to this, I have been around sick people and didn't fork out for the covid shot this year.
I don't understand.

I haven't been sick for over a year, while doing sports/activities most days for the first time.
This cannot be unrelated, but I don't understand the mechanism?