In a statement, the royal household said Margrethe, 82, who has been on the throne for 50 years, canceled her official duties after Tuesday night’s test.
The palace said her eldest son, heir to the throne, Crown Prince Frederik, and his wife, Crown Princess Mary, would take the queen’s place in hosting a dinner with Danish government officials and members of parliament.
Margrethe had already tested positive for the virus in February. At the time, the palace said she received three doses of a COVID-19 vaccine. The Queen was among dignitaries who attended Queen Elizabeth II’s funeral on Monday at Westminster Abbey in London.
Margrethe’s half-century rule makes her Europe’s longest-serving monarch after the September 8 death of Elizabeth, 96, who reigned for 70 years.
Out of respect for the late British monarch, Margrethe had asked her court to tailor the September 10-11 program to its own 50th anniversary commemorations. Among the events she canceled at short notice were an appearance on the balcony of Amalienborg Palace to greet well-wishers and a carriage ride through Copenhagen.
Margrethe was proclaimed queen on January 15, 1972, a day after her father, King Frederik IX died after a short illness.