FWIW, here's my reaction to vaccine shot number 2.

I received Moderna shot two at the Penn Medicine/TLA theatre site in Philadelphia at 8:00 AM on March 13. I was doing a volunteer shift that day, but they had extra's so around 10:00 AM told me I could leave.

Very soon after receiving the shot, I experienced a bit of arm soreness. Less than shot 1, minor, not bothersome at all. It persisted into the next day.

Around 2:00 PM, I began to feel tired. At 4:00 PM, I lay down and slept like a baby for four hours; as I woke up four hours later at 8:00 PM I could barely focus my eyes, I was that sound asleep. I stayed up for a couple of hours, then slept again, soundly, from 10:00 PM to 6:00 AM. So in a 14 hour period I was sound asleep for 12 hours.

I woke up Sunday morning refreshed, a touch sore but I think it was from the long sleep, it went away as I moved about. No fever, no chills, no aches. I took it easy on Sunday and Monday, back to the gym Tuesday. Do discernible after-effects.