What can I do to keep my immune system up. I have Sarcoid of the liver and RA. I have 2 infections since being on prednisone taper for first time.

Immunosuppression. Having two chronic diseases, one is autoimmune, both need prednisone and other meds that cause immunosuppression, having two infections is not uncommon, at any rate you may want to wear a mask while in crowded places, you need to avoid anyhow, stay at a distance from people with colds, don't change diapers for kids who recently received oral polio vaccination, rest, fresh air, fluids,balanced diet.