Pope Francis, 88, suffered two episodes of acute respiratory failure on Monday, requiring medical intervention to clear mucus from his lungs.

He has resumed using an oxygen mask and ventilator but remains alert.

This marks the third serious downturn since his hospitalization for pneumonia 18 days ago.

His illness has prevented him from delivering the Angelus prayer in person for three weeks, and he will miss the upcoming Ash Wednesday mass, the BBC has reported.

Despite Vatican assurances of stability, concerns remain, with Catholics gathering in St. Peter’s Square and outside his hospital to pray for his recovery.

Written by B.C. Begley