Joe Biden, the oldest person ever to serve as US President, has tested positive for Covid-19, is experiencing mild symptoms and will continue working but in isolation, the White House said on Thursday.

Biden, 79, has begun taking a course of the anti-viral treatment Paxlovid, according to his press secretary, Karine Jean-Pierre. “He is fully vaccinated and twice boosted and experiencing very mild symptoms,” she said in a statement.

“Consistent with CDC guidelines, he will isolate at the White House and will continue to carry out all of his duties fully during that time,” she said, referring to the Centers for Disease Control and Prevention.

Multiple members of Biden’s administration and other senior figures in Washington have tested positive for the coronavirus in recent months, including Vice-President Kamala Harris in April, House of Representatives Speaker Nancy Pelosi and attorney general Merrick Garland. All have since tested negative and resumed working. Jean-Pierre said Biden had been speaking with his staff by phone and will continue taking part in meetings by phone and Zoom from the White House while he recovers. He will resume in-person work once he tests negative, she said.