Captain Tom Moore, the 100-year-old British fundraising hero, has been hospitalized with COVID-19.
Moore's daughter said Sunday that he was being treated for pneumonia before testing positive for COVID-19 last week.
The World War Two veteran first captured the hearts of the nation last April by walking laps around his garden, and raising over 30 million pounds, or some 40 million dollars, for the UK Health Service in the process.
Since then, he's broken two Guinness world records, became the oldest person to top Britain's main music chart, and has also been knighted by Queen Elizabeth.
Britain has vaccinated nearly 9 million people against the coronavirus, with the elderly being one of the top priority groups.
But Moore had not yet received a vaccine because he was being treated for pneumonia, according to a family representative quoted by Sky News.
Moore's hospitalisation has prompted an outpouring of support.
Prime Minister Boris Johnson said on Twitter his thoughts were with Moore and his family, saying quote: "You've inspired the whole nation, and I know we are all wishing you a full recovery."