The Queen will continue to do "light" tasks at Windsor Castle during the next week, according to the palace.
"She will continue to receive medical treatment and will adhere to all applicable procedures," the palace said in a statement.
People in the United Kingdom who test positive for COVID-19 must self-isolate for at least five days, however, the British government says it aims to eliminate that restriction for England in the near week.
The Queen has had three doses of the COVID-19 vaccination.
Both her eldest son, Prince Charles, 73, and her 74-year-old daughter-in-law Camilla, Duchess of Cornwall, have just been diagnosed with COVID-19. Since then, Charles has returned to work.
Shortly after her diagnosis was made public, the Queen approved a letter of congratulations to Great Britain's Olympic curling team, praising their success in Beijing.
The Queen, Britain's longest-serving monarch, celebrated her 70th year on the throne on February 6, the anniversary of her father, King George VI's, death in 1952.
Queen Elizabeth has been an important part of the nation's existence and has been in good health for most of her reign. She was observed walking with a cane last year, and in October she spent the night in a London hospital for unclear testing.
The Queen's physicians advised her to take it easy, and she had to forego appearances at funeral services and the COP26 climate summit in Glasgow in November.
This month, she resumed her public responsibilities and met with diplomats, lawmakers, and top army leaders on a genuine and personal level.
The Queen has a full agenda for the next three months of her Platinum Jubilee, including a diplomatic banquet in Windsor on March 2 and the Commonwealth service at the Abbey of Westminster on March 14.
She is scheduled to attend a memorial ceremony at Westminster Abbey on March 29 for her late husband, Prince Philip, who died in April 2021 at the age of 99.
The public Platinum Jubilee celebrations will be up in June, with events such as a military parade, horse racing day, and block parties planned for the long weekend of June 2-5.
The Queen is the most recent monarch in the world to contract COVID-19. Denmark's Queen Margrethe, 82, and Spain's King Philip VI, 54, both tested positive and experienced moderate symptoms earlier in February.