I started having major buzzing from fingertips, up arms, into shoulders, and to the top of my head, like a million bees trapped inside, right after getting COVID, which was 6 days after my first moderna shot. This was April of '21. I've experienced these since then, at first 3 a month, then 2, and now 1. It lasts maybe 5 to 15 minutes, although the first one put me in the emergency room and went half hour. Along with the buzz, I get a crushing feeling in the guts, that would scare anyone, as if "this is it!" After a successful stress test, my doctor said I have the heart of a 20 yr old(64), but thinks it's in my brain, and if it continues, we'll need to talk to a neurologist. Long COVID is a real thing people. I have not, and will not get any more shots.