Hello @visionatsea, Welcome to Mayo Clinic Connect. I also have PMR but it is currently in remission. I have no medical training or background but I don't think you can directly quantify a specific dosage of prednisone to a percentage of risk of compromising your immune system. There is another discussion that may be helpful and more related to your question and you can meet other members asking and discussion similar questions.

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

I haven't seen any PMR specific information for COVID-19. Mayo Clinic has a webpage dedicated to COVID-19 that has a topic for how to reduce your risks -- https://newsnetwork.mayoclinic.org/discussion/reduce-your-covid-19-risk-wash-hands-clean-cell-phones-and-workstations/

Did you see the new Group added to Connect for COVID-19? It has a lot of discussions that you might find helpful during this stressful time -- https://connect.mayoclinic.org/group/covid-19/

Have you read anything about taking prednisone and the risks associated with COVID-19?

That's a great question and I have the same concern - unable to find an answer. Please let me know if you have any new information on this.