Queen Elizabeth, 95, has tested positive for COVID and is experiencing mild symptoms, Buckingham Palace said on Sunday.
"The queen has today tested positive for COVID," the Palace said. "Her Majesty is experiencing mild cold like symptoms but expects to continue light duties at Windsor over the coming week.
"She will continue to receive medical attention and will follow all appropriate guidelines."
Charles, 73, the heir to the throne, earlier this month pulled out of an event after contracting coronavirus for a second time. A palace source said he had met the queen just days before.
The health of the queen, the world's oldest and longest-reigning monarch, has been in the spotlight since she spent a night in hospital last October for an unspecified ailment and then was advised by her doctors to rest.
Elizabeth on Wednesday quipped to members of the royal household that she could not move much as she carried out her first in-person engagement since Charles tested positive.
Thai schools conducted active shooter drills on Wednesday, as authorities moved to strengthen security measures two weeks after a 14-year-old opened fire at a school and killed at least eight people.
At least 21 people have died and four others injured in a head-on collision between a bus and a truck in the BR-373 highway in Brazil's southern state of Parana, the road operator said on Wednesday in an X post.
A Russian drone strike on a minibus in Ukraine's southern city of Kherson has killed four people on Wednesday, Ukrainian authorities said, in what President Volodymyr Zelenskyy described as a "vicious" attack.
The number of confirmed Ebola cases in the Democratic Republic of Congo now exceeds 5,000, government data has showed late on Tuesday, as health officials warn that response efforts are failing to contain the deadly disease.