In his eagerness to reopen the country, President Trump faces the challenge of convincing Americans that it would be safe to go back to the workplace. But the past few days have demonstrated that even his own workplace may not be safe from the coronavirus. Vice President Mike Pence’s press secretary tested positive for the virus on Friday, forcing a delay in the departure of Air Force Two while a half-dozen other members of his staff were taken off the plane for further testing. That came only a day after word that one of the president’s own military valets had been infected. All of which raised an obvious question: If it is so hard to maintain a healthy environment at 1600 Pennsylvania Avenue, the most famous office address in the world, where staff members are tested regularly, some as often as every day, then how can businesses across the country without anywhere near as much access to the same resources establish a safe space for their workers? “The virus is in the White House, any way you look at it,” said Juliette Kayyem, a former assistant secretary of homeland security under President Barack Obama. “Whether it’s contained or not, we will know soon enough. But the fact that a place — secured, with access to the best means to mitigate harm — is not able to stop the virus has the potential of undermining confidence in any capacity to defeat it.” The presence of the virus in both the West Wing and the residential floors of the White House brings home the dilemma facing the nation at a pivotal point in the pandemic. With more than 77,000 deaths in the United States so far and cases rising by the day, states and employers are wrestling with when and how to reopen without putting workers, customers and clients at risk. But the federal government has not detailed the best way to minimize risk, much less avoid more deaths. Even as it has experienced positive tests of its own, the White House has so far blocked the release of a set of recommendations developed by the Centers for Disease Control and Prevention, deeming them overly prescriptive. As a result, businesses have been left to make their best guesses with lives on the line. Both Mr. Trump and Mr. Pence are now tested daily, and both tested negative after the latest infections were discovered. Staff members in proximity to them are also tested daily, as are guests. Congressional Republicans who visited Mr. Trump on Friday were spaced out around the table. Mark Meadows, the White House chief of staff, told reporters that “we’ve put in some additional protocols over the last 48 hours” to reduce the risk and expressed confidence that the president could be protected. “This is probably the safest place that you can come to,” he said. But neither Mr. Trump nor Mr. Pence regularly wears a mask, nor do most of their aides. The president hosted a wreath-laying ceremony at the World War II Memorial in Washington on Friday to mark the 75th anniversary of the victory over Nazi Germany by inviting several veterans aged 95 and over, even though they were in the most vulnerable age group. The latest positive test further rattled a White House already on edge after the president’s military valet came down with the virus. Katie Miller, the vice president’s press secretary and a top spokeswoman for the White House coronavirus efforts, had tested negative on Thursday but then tested positive on Friday morning. The result forced Mr. Pence’s scheduled flight to Des Moines to be delayed for more than an hour, even though she was not traveling with him, so that six other aides who had been in contact with her could be escorted from the plane at Joint Base Andrews before its departure. All six later tested negative but were sent home out of caution, officials said. Ms. Miller is married to Stephen Miller, the president’s senior adviser, and he too was tested again on Friday and the results came back negative. White House officials initially asked reporters not to identify Ms. Miller as the aide who tested positive, but Mr. Trump blew the secret when he identified her publicly during his meeting with the congressional Republicans as “Katie” and “the press person” for Mr. Pence. “She tested very good for a long period of time. And then all of a sudden today, she tested positive,” Mr. Trump said. “She hasn’t come into contact with me. She spends some time with the vice president.” Fox News appearance on Sunday at the Lincoln Memorial and again on Thursday in the Rose Garden. Her husband is in meetings with the president even more frequently as the architect of his crackdown on immigration, although he and other aides have sat farther away than they have in the past. Multiple presidential aides are now tested daily, as are about 10 members of Mr. Pence’s staff, an official said. But tests are conducted less frequently on other White House officials who work next door in the Eisenhower Executive Office Building and have regular contact with West Wing aides even if not the president himself. The Secret Service has 11 active cases of the coronavirus and 23 employees who have recovered, current and former government officials said Friday, but it was unclear whether any were agents or served in the White House. The service, which has 150 offices across the country responsible for protecting a variety of dignitaries and investigating financial crimes, also has 60 others undergoing self-quarantine, Yahoo News reported. While tested regularly, agents in the president’s detail have not been wearing masks, and new faces have shown up in recent days. The White House infections further inflamed the national debate about testing even as many states begin lifting restrictions on businesses and social gatherings. Mr. Trump has said testing is adequate for reopening even as public health experts said it must be much more robust to have a better map of the outbreak. The Harvard Global Health Institute estimated this week that the United States needs to do at least 900,000 tests a day by May 15, but is only doing about 250,000 now. “One of the most important ways to protect our workers is by conducting more tests,” said Lorraine M. Martin, the president of the National Safety Council, a nonprofit advocacy group. “Increased access to Covid-19 testing for our work force will help flatten the curve by removing people with coronavirus from the workplace and better ensure the safety and health of employees who are maintaining operations during this pandemic.” But on Friday, Mr. Trump cast doubt on testing as a panacea, saying Ms. Miller’s case at the White House demonstrated the limits of its utility. “This is why the whole concept of tests aren’t necessarily great,” the president said. “The tests are perfect, but something can happen between a test where it’s good and then something happens and all of a sudden” it is not. Some experts said he has a point. “People need to understand the limitations of testing,” said Nellie Brown, the director of workplace health and safety programs at the Worker Institute at Cornell University, who is advising businesses on how to reopen safely. “When you take a test you’re basically getting a slice in time. You know what is happening at that moment, but you don’t know what may happen even soon after that.” Even so, she said, the president should be setting an example for the rest of the country, like by wearing a mask. “You need to model the behavior you want others to exhibit because you’re so powerful an example,” she said. “It’s so important for others to see we’re all doing this because we’re all in this together.” White House valet who tested positive for the coronavirus. He said that the aide, who is in the Navy, had not worked for several days before Tuesday, when he was “in the room” with the president for an unspecified amount of time before discovering that he was carrying the virus. “I don’t think any contact,” Mr. Trump added of his interactions with the aide. After some prompting, the president cheekily offered to send a test kit from the White House to his likely Democratic opponent in the general election, former Vice President Joseph R. Biden Jr. That, he said, would allow Mr. Biden to “get out of the basement so he can speak,” adding that “every time he talks, it’s, like, a good thing.” Source