That's quite a reaction to the Covid vaccine. I had a pretty bad reaction to it, too. I was sick for a couple of days. I'm afraid to get the Shingles although everybody advises it, because I've heard of some horrific reactions. I do believe some people are more susceptible to flu than others. My father, like me, got it every year. My mother never had it and my sister never got it. Maybe people are getting sick all the time because of no natural immunity. It's something to think about.