My very first Covid vaccine caused my PMR. I got my first in June 2021 on my sons birthday. It took about 24 hrs and I felt like my neck was out. Pain throughout my hips back neck and headache. I am still battling, started with 15 mg prednisone, relapsed back to 20 mg and now down to 10 mg. It’s a long haul for most folks that I have read about on here. I too worry about side effects but what do you do? I am trying to ramp down by 1 mg every two to three weeks. Every time I drop 1 mg my body aches and pains flair for a day or two. Not severe, you just have to keep going and my body has been correcting. I Am told from 10 down will be the real hard times. Never give up. If you start hurting bad, go back up for A few days or a week and keep working at it. I split my 10 mg dose. I take 5 in the morning and 5 at supper time and that helps a lot.
I cannot do another vaccine as it scares the hell out of me. Good luck. Talk to lots of good folks on here. Lots of knowledgeable people.