How long until side effects kick in from the pfizer vaccine (in hours)?

I felt weird starting about 7 hours afterwards. The next morning I felt fine though. That was the first dose. I’ll find out in a couple weeks about the second. 

My wife had a head ache within hours, actually it was starting by the time she got home and it was about an hour drive to where she could get the shot. That was pretty much it, woke up the next day and said it was gone, might not have even been from the shot, might have been from being in the car for so long.

Mostly, they don't......

Could be as early as 15 minutes. That’s why you’re told to stay at the site for at least 15 minutes before you go home. That’s like the worst case scenario where someone becomes allergic or have an adverse reaction to the vaccine. 

Your arm will probably feel sore within the hour but that’s a very minor effect. You probably don’t even notice it if you get it injected on your non-dominant arm (left arm if you’re a right hander, right arm if you’re a lefty). 

Fever and chills probably won’t kick in until about 2 hours later. I got my shot at 6 pm and didn’t feel the chills until the next day.

You should plan to take the day off just in case you have a major side effect. Most people only experience a sore arm and maybe a headache after the first shot.