I think in general one's allergies tend to get worse as one gets older. For instance, I'm allergic to a lot of things now that I was not allergic to as a kid: penicillin, cat/horse/dog/cow danders (though I'll be darned if I'll give up my dog!), dust, etc. I think it all depends on what you've been exposed to in your life, and how your body reacts to it. I had at least three small pox vaccines when I was young, no problem. I have no idea how I'd react to it now. Still, I'd much rather take my chances with the vaccine than with the bug (one in a million chance I'd die vs. one in three -- Plus if the president orders it -- not that I'm especially brave, mind you! -- I'll gladly do it . . . duty and all, 'ya know?). Cheers!