“It is scary to go to work,” Kevin Hassett, a top economic adviser to the president, said on CBS’s “Face the Nation” program on Sunday. Mr. Hassett said he wore a mask at times at the White House, but conceded that “I think that I’d be a lot safer if I was sitting at home than I would be going to the West Wing.”

He added: “It’s a small, crowded place. It’s, you know, it’s a little bit risky. But you have to do it because you have to serve your country.”…

Most restaurants, offices and retail stores do not have the ability to regularly test all their employees and quickly track down and quarantine the contacts of anyone who gets infected. At the White House, all employees are being tested at least weekly, officials said, and a handful of top aides who regularly interact with the president are being tested daily, they said.

“To get in with the president, you have to test negative,” Mr. Hassett said on CNN’s “State of the Union” program.