One of the doctors treating Pope Francis said the 88-year-old, who has pneumonia, is "not out of danger" and would likely stay in hospital "at least all next week".
Professor Sergio Alfieri said the pontiff's condition was "slightly better" but added that "the pope is not out of danger", at a press conference one week after Pope Francis was admitted with breathing difficulties.
Prof Alfieri explained that the pope is not in danger of death but is not yet cured.
"Is he out of danger? No. But if the question is 'is he in danger of death', the answer is 'no'," Prof Alfieri said.
Pope Francis is being treated at Rome's Gemelli hospital, where he was admitted on 14 February after struggling with breathing difficulties for several days.
Double pneumonia is a serious infection that can inflame and scar both lungs, making it difficult to breathe.
The Vatican has described the pope's infection as "complex" because it is polymicrobial, meaning it is being caused by two or more micro-organisms.
His medical team said the pope was able to get out of bed and sit in an armchair to do some work.
Prof Alfieri, on the medical staff at Gemelli, said that given the pope was 88, with prior health concerns, he was obviously a fragile patient.
He said that the pope did not have sepsis, a potentially life-threatening condition when the body responds to an infection by harming its own tissue and organs.
However, Prof Alfieri said the pope was still at risk that his infection could spread from his respiratory tract to other parts of his body.
This press conference was the first with the medical team since the pope was admitted to hospital last week.
No photos of Francis have been released out of respect for the pontiff's privacy, Prof Alfieri said.
The doctors comments came after the Vatican said yesterday evening that the pope's condition was "slightly improving" for the second day in a row.
Resignation a 'distant hypothesis'
Pope Francis, who has been pope since 2013, has suffered bouts of ill health in the past two years.
He is particularly prone to lung infections because as a young adult he developed pleurisy and had part of one lung removed.
One retired Catholic cardinal suggested that Pope Francis' fragile health could lead him to resign as leader of the 1.4 billion-member Catholic Church, as his late predecessor Pope Benedict XVI did.
But Pope Francis has firmly ruled out resigning in the past, calling it in 2024 only a "distant hypothesis".
Church law also requires that any papal resignation be "freely and properly manifested", meaning a pope's decision to step down cannot be influenced in any way by outside pressure.
Pope Francis is known for keeping a brisk schedule, sometimes holding dozens of meetings a day.
Vatican officials expect his latest health crisis may lead him to slow down the pace a bit.
All the pope's public engagements have been cancelled through Sunday and he has no further official events on the Vatican's published calendar.
Vatican sources have said the pope continues to keep up with his correspondence and has been working with his collaborators.
Cardinal Matteo Maria Zuppi, the head of Italy's bishops conference, expressed confidence yesterday that the pope was "on the right path".
"The fact that the pope had breakfast, read the newspapers, received people, means that we are on the right path to a full recovery, which we hope will happen soon," Cardinal Zuppi said.
With instructions from doctors for "absolute rest", the former Jorge Bergoglio had cancelled his engagements for the week, including an audience tomorrow and mass on Sunday at St Peter's Basilica.
Still unknown, however, is whether the pope could lead the traditional Angelus prayer at midday on Sunday from the Gemelli balcony, as he has done during previous spells at the hospital.
Last Sunday, the Vatican published an Angelus that was written, but not read, by the pope.
Candles, photos
During his hospitalisation, some Catholic faithful have set up candles and photos of the pope in front of a statue of Pope John Paul II outside the Gemelli hospital.
The vicar general of the Diocese of Rome, Cardinal Baldassare Reina, has called on all parishes within the capital to pray for Francis' recovery.
But despite his diagnosis, the pope has been in good spirits, a Vatican spokesman said earlier this week.
One high-profile visitor was Prime Minister Giorgia Meloni, who after her 20-minute visit on Wednesday, reported him "alert" and even joking.
"He hasn't lost his proverbial sense of humour," said the far-right leader.
Pope Francis has been plagued by health issues in recent years, including multiple bouts of bronchitis, hip and knee pain and colon and hernia surgery.
His current hospital stay is his fourth to the Gemelli since 2021.
