King Carl XVI Gustaf and Queen Silvia of Sweden and Grand Duke Henri of Luxembourg have all tested positive for COVID-19, their royal households have confirmed.
In a statement on the Swedish royal family's website on Tuesday, it stated that the monarch, 75, and his wife, 78, who are fully vaccinated with three doses, are experiencing mild symptoms.
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The couple tested positive for the virus on Monday night and are currently isolating at their home.
It comes as Sweden registered a record new 11,507 cases on 30 December, Reuters reports.
Meanwhile, Grand Duke Henri, 66, will carry out his royal duties remotely while he is in isolation at Berg Castle in central Luxembourg.
The head of state is married to Grand Duchess Maria Teresa and the couple share five children.
King Carl and Queen Silvia's son, Prince Carl Philip and his wife, Princess Sofia, had COVID-19 in November 2020, while their daughter, Crown Princess Victoria and Prince Daniel, tested positive for the virus in March last year.
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King Carl and Queen Silvia at Sweden's Nobel Prize ceremony on 10 December
It comes as the British royal family celebrated another low-key Christmas due to rising coronavirus cases.
The Queen cancelled her pre-Christmas family lunch and remained at Windsor Castle for the festive period, instead of travelling to Sandringham as tradition. She was joined by her eldest son and heir, the Prince of Wales and the Duchess of Cornwall, on Christmas Day.
Meanwhile, the Duke and Duchess of Cambridge celebrated Christmas at their Norfolk abode, Anmer Hall, with Kate's parents, Carole and Michael Middleton. The Cambridges were pictured leaving a church service in Sandringham with their three children, Prince George, Princess Charlotte and Prince Louis.
The Queen's daughter, the Princess Royal, was unable to spend the festive season with her mother as her husband, Vice Admiral Sir Timothy Laurence, tested positive for COVID-19 just days before Christmas.
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