The Duke of Edinburgh stepped back from royal duties at the age of 96 after completing 22,219 solo engagements.
However he recently issued his first public statement since retiring, and thanked key workers in the UK for their hard work during the pandemic.
He said: “As we approach World Immunisation Week, I wanted to recognise the vital and urgent work being done by so many to tackle the pandemic.
“By those in the medical and scientific professions, at universities and research institutions, all united in working to protect us from COVID-19.
“On behalf of those of us who remain safe and at home, I also wanted to thank all key workers who ensure the infrastructure of our life continues.
“The staff and volunteers working in food production and distribution, those keeping postal and delivery services going, and those ensuring the rubbish continues to be collected.”
Meanwhile, a new report claims doctors are on standby for Prince Philip amid the coronavirus pandemic.
The 98-year-old is said to be "enormously vulnerable" to coronavirus, which has resulted in has doctors being on standby.
"Prince Philip is enormously vulnerable, as he is a very sick person anyway," royal expert Angela Mollard revealed to the Express.co.uk.
She continued: "He was in hospital at Christmas time, so they will be protecting his health at Windsor. There will be doctors on staff."
Her Majesty and Philip will reportedly have a significantly reduced amount of staff.