Hello Marianne @daisy12345, Welcome to Mayo Clinic Connect, a welcoming online community where patients and caregivers share their experiences, find support and exchange information with others. My PMR has been in remission for a few years. I have had both Pfizer vaccines and received my second shingles vaccine yesterday and feel lucky to only have the "normal" side effects of a sore arm and some fatigue after the second day of the second Pfizer shot. You are not alone though, others here have reported an autoimmune flare up after receiving the vaccines and have posted about their experience in the following discussion.

Polymyalgia Rheumatica (PMR), prednisone and Coronavirus COVID-19: https://connect.mayoclinic.org/discussion/coronavirus-and-pmr/

There's also information available supporting the relationship to flu vaccines in general.
-- Polymyalgia Rheumatica After Influenza Vaccine: https://www.journalmc.org/index.php/JMC/article/view/2788/2121
-- Relapse of polymyalgia rheumatica following adjuvanted influenza vaccine: A case-based review: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7002008/

Has your rheumatologist suggested a new tapering schedule for getting off of prednisone?

Hi Marianne - so sorry to hear you’ve had a relapse. I’m also new to this site. I developed PMR like symptoms following my first Pfizer jab. I also had a chest infection so was not out on prednisolone for 8 weeks. I started off at 20mgs abd am now down to 10mgs for 6 weeks and then to 5mg/10mgs on alternate days, but have noticed shoulder aches and swelling in hands again.
Am guessing there is definitely a link to the vaccine and have been advised not to have a 2nd. As I said I am new to all this and finding my way but reassuring to read other people’s stories
All the best
Kate