The Duchess of Cornwall has said the Duke of Edinburgh is "slightly improving" in hospital as she carried out a visit to a community vaccination centre.
The Duke of Edinburgh is "slightly improving" but "hurts at moments", the Duchess of Cornwall revealed.
On a visit to south London, Camilla said of her 99-year-old father-in-law: "We keep our fingers crossed."
Philip, the nation's longest-serving consort, has spent 15 nights in hospital - his longest ever stay.
The Duke was taken from King Edward VII's Hospital to St Bartholomew's Hospital on Monday morning. He is undergoing tests for a pre-existing heart condition and treatment for an infection.
Buckingham Palace said doctors would continue to treat him for an infection but would also "undertake testing and observation for a pre-existing heart condition".
The Duke was carefully shielded as he left the private King Edward VII hospital in London. Large umbrellas were used as a protective screen as he was transferred into a waiting ambulance.
The Duchess's comments were reported by broadcasters covering her engagement on Wednesday morning at a community vaccination centre in Croydon.