Feel great when starting to get sick- anyone else?

Heds here. Received my Covid and flu vaccine today. After briefly being light headed, came home and felt fantastic the rest of the night. In fact every time I get a vaccine or start getting sick, I feel great- chronic headache and joint pain significantly reduces, etc. It’s so drastic that I can immediately tell when I’m getting sick, because I feel too abnormally good. Always figured it was my immune system saying “what the heck is going on” before soldiering the white blood cell troops to start a war, where I subsequently feel abnormally horrific. Anyway- thought I read in one of these threads there’s potentially an Eds and immune link, wondering if anyone else has experienced this type of feel good pre-sickness?