janiceem,
That's a shame about your friend. I too have never had the flu shot, and have only had the flu twice in 40 years.
I did a lengthy post a while back on my adverse reaction following my second Pfizer Covid shot in March of 2021. I was 68 years old at the time and never had any type of arthritis. (In fact, I was actually able to run sprints a month before I got the first shot!) The adverse reaction expressed as gout symptoms, for which prednisone and colchicine had only minor and temporary effect on the pain and swelling in my left foot. My uric acid level was normal, but even though gout can occur without elevated uric acid, it obviously was not actual gout, since It took about 5 months to run its course. After that, I was symptom free until late March of this year.
About 2 weeks after a plane flight in March of this year, pain and swelling started off in my left wrist, and over about the next 2 months, spread to numerous other places indicative of various other types of arthritis, but again the initial blood work or other means taken after the symptoms started did not indicate the presence of actual arthritis. It has been established that plane flights (perhaps due to the effects of reduced air pressure) can trigger autoimmune disorders. (But since I didn’t have any autoimmune disorders before the shot, did it create one??) I did two 8-day rounds of prednisone this summer, which worked well (40mg down to 20mg). But the symptoms returned both times. I am now on a lower dose of prednisone (20mg down to 10mg) for a longer period that my PCP prescribed, and will continue on that until I see my new rheumatologist on 10/20. Hopefully, this “round 2” will have run its course by the time I quite taking the prednisone. But if it hasn't, I hope I can convince the rheumatologist to try to determine and attack the cause, and not just treat the symptoms. But I’m not getting my hopes up about that.