Well if it adds anything...work put on flu shots for everyone the thursday before the easter long weekend. Friday was ok, and then spent the saturday, sunday and monday bed ridden and feeling like death in general. For context I rarely get sick also, eat well, exercise regularly etc. Ruined the whole long weekend for me.
Flu shots have burned their bridge for me now; never again. I'll look back into it when I'm in my old age or I've developed a debilitating disease.