US Vice President Kamala Harris and her husband Second Gentleman Doug Emhoff wave upon departure from Vandenberg Space Force Base where Harris delivered a speech at the Command Space Center in Lompoc, California. AFP
"Today, Vice President Harris tested positive for Covid-19 on rapid and PCR tests. She has exhibited no symptoms, will isolate and continue to work from the vice president's residence," said Harris' press secretary, Kirsten Allen.
"She has not been a close contact to the president or first lady due to their respective recent travel schedules," Allen said, adding that Harris would "return to the White House when she tests negative."
Biden spoke with Harris by phone, and he "wanted to check in and make sure she has everything she needs as she quarantines at home," a White House statement said.
Press Secretary Jen Psaki said Biden, 79, tested negative for Covid on Monday.
Harris, 57, is the latest in a rash of cases sweeping through the Washington elite, with multiple members of Congress also announcing positive tests on Tuesday.
The vice president's husband, Doug Emhoff, came down with Covid in March, although Harris herself remained negative.
As infections from the virulent, but dramatically less dangerous, Omicron variant of the coronavirus mount, the White House has publicly aired the possibility of Biden testing positive -- while downplaying any potential fallout.
"It is certainly possible that he will test positive for COVID, and he is vaccinated, he is boosted and protected from the most severe strains of the virus," White House communications director Kate Bedingfield said earlier this month.
"Any American could get Covid," the new White House Covid-19 response coordinator Ashish Jha told reporters. "We have a very, very contagious variant out there."
Other high-profile cases in Washington recently include White House press secretary Jen Psaki, who contracted Covid in March and also last year, as well as House of Representatives Speaker Nancy Pelosi, who comes after Harris in the line of succession to the presidency.
In October 2020, before vaccines were available, then president Donald Trump spent three days in hospital receiving emergency treatment for Covid-19, which he had told Americans was not a danger.
More than 900,000 people in the United States have now died from Covid-19, which at its peak killed over 3,000 a day. Currently about 300 to 400 people die from Covid every day in the world's richest country.