Got dose 1 of the Pfizer vaccine this past Monday; IM, the actual injection hurt way less than the annual flu shot, though within about 5 hours my arm was pretty sore, more so than the flu shot. Soreness continued all the next day, gone day 3. No other symptoms.
I personally know dozens of people that have had it, no one with anything more than sore arm for 1-2 days.
I have questions as anyone should RE mRNA vaccine tech as this is the first widespread use beyond early clinical trials, but all the research I’ve done has put my mind at ease and I’m fine with it. Obviously no super long term studies but the only thing I imagine might play a role is rare potential immune problems, which can happen with other kinds of vaccines as well (eg. Antibody dependent enhancement).