The pope's infection will require further hospitalization, the Vatican said Monday, as concerns grew about the increasingly frail 88-year-old pontiff.

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

Pope Francis’ respiratory infection is presenting a “complex clinical picture” that will require further hospitalization, the Vatican said Monday, as concerns grew about the increasingly frail health of the 88-year-old pontiff.

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

Francis was serene after arriving at Rome’s Gemelli hospital after presiding over his morning audiences, Vatican spokesperson Matteo Bruni said.

The Vatican said the results of recent tests indicate the pope is suffering from a polymicrobial respiratory tract infection that has necessitated a further change in his drug therapy.

Vatican spokesman Matteo Bruni said the results of tests conducted in recent days and Monday indicate the pope is suffering from a “polymicrobial respiratory tract infection” that has necessitated a further change in his drug therapy.

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

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

The pope's weeklong bout of bronchitis worsened, said the Vatican, which also announced the pope was canceling his participation in Holy Year events through Monday.

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

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