My PMR came back after my second Moderna vaccine. I had been taking prednisone for 14 months, prior for my first bout of PMR - was only off prednisone for 1 month. I’m now down to 8 mg, and chose to get the booster today. I’m hoping that the 8 mg will suppress any PMR reaction, but I’m prepared to go back up to 15 and wean down again, if it does. I’ll keep you posted.