I've read that generally older people on average have less side-effects. Thankfully my mom and stepdad reported almost none. Glad that many read here have not or reported minimal/mild
Myself, 44M, and got 2nd Pfizer shot Tues 3/9/21, have not been lucky. Have had the gauntlet of side-effects. Had to take a sick day off work 3rd day. This is day 5 and waking up with now unpleasantly usual rear headache (behind ears) and neck pain. 325 mg Aspirin has become common.
I doubt anything can be done but hope effects peters out in the next 2-3 days. The longer it goes, the more worrisome - seems to be a bit of diminishment or I could be telling myself that. The headache is low-to-moderate, and at least not in the temples or brows - its less bothersome at rear.
1st Pfizer shot had no additional side-effects besides sore-arm.