Re: I dont get stomach flu...why?
I also don't get it.
I'm 21.
I remember getting it twice in the 90s (1996 and 1998) - in memory, I've probably vomited and/or had it when I was a baby/toddler in the early 90s.
Twice again in the 2000s - very briefly in 2001/2002 (dunno which year exactly) and the MOST BIGGEST, WEIGHT LOSING, LIFE DRAINING, LIFE SUCKING, DEPRESSING, LONGEST ONE was in July 2008 - oh God it ruined my life. It went for 2 weeks and I didn't vomit it at all (lucky that we emets have this technique of holding it back). I lost 8 kilos and now I'm still underweight. It was my personal '9/11'.
Since it seems like I don't have the stomach flu much I believe yes, some of us are not prone to it as others are. It depends on our blood type I guess.
Re: I dont get stomach flu...why?
Certain blood types have partial or complete immunity to certain strains of norovirus (I forget which ones).
My theory is that we emets take better care to avoid getting sick in the first place, but we can't avoid exposure completely so there's gotta be more to it. My dad (an emet) has only gotten stomach virus TWICE in my life; only once did he vomit. He and I were always the last ones in our house to get sick, IF we did at all. His symptoms were always less severe than the rest of my family's too. Grandpa (another emet) hasn't been v*ed since the 1970s and rarely gets sick at all.
The immune system is amazingly complex. I'm sure there are factors scientists don't fully understand. (I'm always baffled by the spouses of HIV sufferers who never get the disease despite repeated exposures).