As an asthmatic, my mother used to mandate I get the flu vaccine every year.
When I left home, and as an adult, I always got the flu vaccine...until...
At bout 48 years old (7 years ago), I stopped getting the flu vaccine once. Haven't had the flu once. Probably should get it (you know, every 'reputable' source says you should). After not taking it and not getting the flu, I asked a simple question - why take it? I don't get it when I don't take it. I don't get it when I do take it. So far, after 7 or 8 years, I've been absolutely fine.
Won't be for life, of course.
More important than vaccines are exercise and diet and a regimen of supplements, each of which I do. Exercise 5-6 days a week, lost 40lbs, take D, Zinc, Quercetin, Magnesium, C, rose hips, milk thistle, etc.
Outside of one bout of Covid 2.5 years ago that was mild to moderate, I haven't had a cold in 4 years, no flu in like 10.
The vaccine you're taking may have kept you from getting the flu. The vaccine I've not taken hasn't led me to get the flu either.