I had my Pfizer booster on Monday at work, courtesy CVS. I had a somewhat worse reaction than the 2nd shot. I had the booster shot around 11am and felt the soreness in the arm when I was driving home around 8:30pm. I felt heavy headed and took an Advil. Yesterday, the whole afternoon I felt chills and some lower back aches and also slight head ache. I'm feeling okay now. Still some soreness around injection point.
A couple of guys in my group got fever. I think most people get a worse reaction from the booster shot. Maybe because it's the weather. I also got the flu shot at the same time.