Pope Francis, who is being treated for a respiratory infection, spent a peaceful night at Rome's Gemelli hospital, Italian media reported, as a senior cardinal led prayers for his recovery.
The 88-year-old Francis will not appear in public on Sunday to celebrate his usual weekly prayer with pilgrims because he has been advised to rest.
The pontiff has been suffering from bronchitis for more than a week and was admitted to hospital on Friday morning.
„Our first thought is for Pope Francis. "We pray for his health, thanking him for the vision and support he always gives us," Cardinal José Tolentino de Mendonca said during a Mass in St. Peter's Basilica on Sunday. The cardinal was leading the Mass, which honors artists during the Catholic Church's Holy Year, in Francis' absence. A Vatican statement released late Saturday said the pope had been "prescribed complete rest" to aid his recovery. The pope's treatment on Saturday was "slightly modified based on additional microbiological findings," the statement said. “Today's laboratory tests showed an improvement in some values“, it added.
The Vatican said the pope would remain in hospital for as long as necessary for his treatment.
Francis, who has been pontiff since 2013, has had flu and other health problems several times in the past two years.