The Vatican says Pope Francis’ respiratory tract infection is presenting a “complex clinical picture” that will require further hospitalization.

Pope Francis has been in the hospital since Friday with a respiratory tract infection. Officials with the Vatican said Monday that the 88-year-old’s infection requires further hospitalization and a change in drug therapy. Francis has had several health ailments over the years.

Pope Francis, who is in critical condition in hospital battling double pneumonia, rested well throughout the night, the Vatican said on Tuesday. The 88-year-old pope was admitted to Rome's Gemelli hospital on February 14 with a serious respiratory illness that has since triggered other health problems.