My primary care doc said I should get the 2nd shot of Covid vaccine and to change the manufacturer. My first dose was Pfizer and within a couple of days I was in misery. That was over a year ago. I just got my prednisone dose down to 4.5 mg and had the 2nd shot today. I got Moderna this time. Fingers crossed! Next I get to start on letrosole after having had a lumpectomy. Side effect? Joint pain. I'm just going slow and observing and keeping my fingers crossed - and the prednisone handy.