The American Society of Health-System Pharmacists reports a shortage of prednisolone tablets. If you look at the link, however, only prednisone tablets are listed. They are not the same, the liver converts prednisone into prednisolone, which is the active form. If someone has a liver disease or insufficiency, they are given prednisolone for this reason.
Whichever is actually in short supply, there are now related shortages of hydrocortisone sodium succinate for injection, methylprednisolone acetate for injection, and dexamethasone sodium phosphate