It seems the younger you are the worse it is. My daughter felt lousy for 48 hours. DH and I had maybe a bit of fatigue but nothing impressive
I’m not sure. It’s probably unique to the individual.
I’m 67. The night and first day after the second shot were pretty bad - I just curled up in a ball in bed and couldn’t move anything without pain. I”ve had much worse fevers with ‘flu, but nothing to compare with the muscle and joint pain. Second day was much better but still bad. After that, I was fine.
My husband is 14 years younger - he had fever and muscle aches for most of the first day after the shot, then he was fine.