Supposedly the Pfizer version makes a fair number of recipients feel down for 2-3 days. The Moderna approach had much less of that, I don't know why. That's the only side effect we know of today. I doubt any show up in say 6 months after mass vaccinations. (I doubt any show up period really.)
I personally will be in line when my time comes around. It's a bit selfish I suppose, but part of our lives is travel, and that has been wiped out this year except a month long trip to France in Jan/Feb., which is not the best time to visit France.
It's been a good year for me financially in part because I'm spending less money and in part because I was fortunately with some stocks, but I can't spend it. If we get vaccinated and travel, I may be gone a while.