Britain's monarch Queen Elizabeth II and her husband Prince Philip have been inoculated with a COVID-19 vaccine, Buckingham Palace has confirmed. The royal couple received their vaccinations on Saturday at Windsor Castle where they have been isolating since the start of the pandemic. The Queen, 94, and the Duke of Edinburgh, 99, both fall in the high-risk age group being prioritized for vaccination by the UK government. The Queen "decided that she would let it be known she has had the vaccination," the palace statement said. Royal officials said they took the rare step of commenting on the monarch's health in order to prevent inaccuracies and further speculation. The vaccines were administered by a doctor from the Royal Household. It is not known what vaccine the couple was given. On Dec. 8, Britain became the world's first country to begin a mass vaccination drive against the coronavirus. The UK government says it is aiming to deliver the first vaccine doses to some 15 million people in the top priority groups by the middle of February. That includes everyone over age 70, as well as frontline health care workers, care home residents and anyone whose health makes them especially vulnerable to the virus. So far, some 1.5 million people in the UK have been given a first dose of a vaccine. The British monarch made her first public appearance outside a royal residence in October, appearing alongside Prince William at UK's Defense Science and Technology Laboratory to officially open its new Energetics Analysis Centre. Her last official public engagement was on March 9 when she joined senior royals for the Commonwealth Day service at Westminster Abbey. The Queen has continued to carry out her official duties throughout the pandemic online through video calls. The Queen's eldest child and heir, Prince Charles, 72, tested positive for coronavirus at the end of March and self-isolated at his Scottish residence Birkhall with mild symptoms. It was revealed in November that his son Prince William, 38, also tested positive in April just weeks after his father but kept his diagnosis a secret for six months to avoid alarming the public. The Duke of Cambridge's case was believed to be so bad that he struggled to breathe, although his diagnosis has not been officially confirmed by Kensington Palace. The news of the Queen's vaccination comes after Queen Margrethe of Denmark became the first European sovereign to officially announce that she had received the first dose of a coronavirus vaccine on Jan. 1. The Danish queen, 80, was among the first cohort of Danes to be vaccinated against the virus. — Euronews