I had my Moderna Vax in February and March and was diagnosed in April with PMR. My doctor started me right away on the prednisone, at 15 mg. a day and within one day I started to get full relief. I couldn't believe the difference in my pain level from 10 to 1 in one day!! In all fairness my symptoms started in December, but got gradually worse through April. So I think the vaccination probably had nothing to do with it. I did have a flu vaccination in October though. Hope you get on prednisone quickly. It makes all the difference in the world. Before I started it, I couldn't even get out of a chair without help.