Pope Francis looks on during the weekly general audience on October 23, 2024, at St Peter's square in The Vatican.

CNN  — 

For the first time since his hospitalization around three weeks ago, Pope Francis is showing a good response to treatment, a Vatican source told CNN.

This follows a statement from the Vatican press office on Saturday that described “a good response to therapy” and a “gradual, slight improvement” since his episodes of acute respiratory failure on Monday.

The Vatican source said that this improvement was due to the “gas exchange” in the lungs and the oxygenation of the blood. However, the risk remains of another breathing crisis remains and the prognosis is still reserved, the source emphasized.

The pope continues to alternate between high flow oxygen therapy during the day and non-invasive ventilation at night, the Vatican press office said.

On Saturday morning, Francis prayed inside a chapel. In the afternoon, he rested and engaged in work activities, the office said.

On Sunday Francis took part in mass at the chapel on the 10th floor of Rome’s Gemelli hospital, then took part via video feed in the “spiritual exercises” taking place at the Vatican for Lent, the Holy See Press Office said.

A Vatican source said Francis remained connected to the video feed for the duration of the meditation and was able to see members of the Curia – Vatican bureaucrats – but did not communicate with them. According to the source, the pope’s medical condition remains the same as on Saturday, with the 88-year-old pontiff experiencing stability and slight improvement but still having a “complex overall picture.”

Since Monday’s incident, the pope has remained in stable condition and received respiratory and motor physiotherapy. He released a pre-recorded audio message on Thursday thanking his supporters for their prayers.

Uncertainty has continued to swirl in the Vatican throughout Francis’ extended hospital stay.