Pope Francis's condition showed "a further, slight improvement", the Vatican said Wednesday, while continuing to maintain the prognosis for the 88-year-old fighting pneumonia in both lungs was "reserved".

Pope Francis, 88, was hospitalized last Friday with bronchitis, the Vatican said, and now has a “polymicrobial infection of the respiratory tract.”

The Vatican said Pope Francis has the "onset of bilateral pneumonia," and that tests, a chest X-ray and the pope's clinical condition present a "complex picture."