Pope Francis, battling double pneumonia in hospital, is in a stable condition and has shown “slight improvement” in results from recent blood tests, the Vatican says.

The 88-year-old pontiff is being treated at Rome’s Gemelli hospital, where he was admitted on February 14 after struggling with breathing difficulties for several days.

“The clinical conditions of the Holy Father are stable,” said a brief Vatican statement on Wednesday.

“Blood tests … show a slight improvement, particularly in the inflammatory markers.”

Double pneumonia is a serious infection that can inflame and scar both lungs and makes breathing more difficult.

The Vatican had said previously that the pope had a polymicrobial infection, which occurs when two or more micro-organisms are involved. The Vatican said he would stay in hospital as long as necessary to tackle a “complex clinical situation”.

Francis received a visit earlier in the day from Italian Prime Minister Giorgia Meloni, who said he was “alert and responsive,” and had joked with her.

“He hasn’t lost his proverbial sense of humour,” said Meloni, the pope’s first known visitor in hospital.

A Vatican official, who did not wish to be named because he was not authorised to speak about the pope’s condition, said earlier on Wednesday (local time) that Francis was not on a ventilator and was breathing on his own.

The official said the pope had been able to get out of bed and sit in an armchair in his hospital room, and was still doing some work.

Messages of support for Francis had come in from around the world, the Vatican’s official media outlet reported. Pilgrims at the Vatican on Wednesday for the pope’s cancelled weekly audience expressed hope for his recovery.

“We will pray for him so that he can recover as soon as possible,” said Gianfranco Rizzo, a pilgrim from Bari, Italy.

The pope has been plagued by ill health in recent years, including regular bouts of flu. He is especially prone to lung infections because as a young adult he developed pleurisy and had part of one lung removed.

All the pope’s public engagements have been cancelled until Sunday. He has no further official events on the Vatican’s published calendar.

Gemelli hospital, Rome’s largest, has a special suite for treating popes, and is known especially for often treating the late Pope John Paul II during his long papacy.

Francis spent nine days at Gemelli in June 2023, when he had surgery to repair an abdominal hernia.

Outside the hospital on Wednesday, people left flowers and personal notes under a statue of John Paul II, wishing Francis a speedy recovery.

Victoria Darmody, a tourist from England, said she came to the hospital just to be near the pope.

“We were hoping to go to the papal audience today but felt this was the right place to be instead,” she said.

Andrea Vicini, a Jesuit priest and medical doctor, said it was notable that the Vatican’s statement referred to the pontiff as having the onset of pneumonia and not bronchopneumonia. The latter would indicate an infection that was more widespread, he said.

“It [sounds like] it’s more localised and has not spread,” said Vicini, a professor at Boston College, who said he did not have details of the pope’s case beyond the Vatican’s public statements.

“If they identified the pathogen, as I expect they would have done, they will have a very targeted therapy,” he said.

“I am optimistic. It seems they are controlling what is happening.”

Work at the Vatican continued as the pope was in hospital. One senior official, Cardinal Michael Czerny, left on Wednesday for a five-day visit to Lebanon.

The Vatican’s top diplomat, Cardinal Pietro Parolin, returned to Rome as scheduled on Wednesday from a trip to Burkina Faso.

-Reuters