It is a delicate decision balancing employee health and personal privacy. Some companies are sidestepping the issue by offering incentives to those who get shots.As American companies prepare to bring large numbers of workers back to the office in the coming months, executives are facing one of their most delicate pandemic-related decisions: Should they require employees to be vaccinated?Take the case of United Airlines. In January, the chief executive, Scott Kirby, indicated at a company town hall that he wanted to require all of his roughly 96,000 employees to get coronavirus vaccines once they became widely available.“I think it’s the right thing to do,” Mr. Kirby said, before urging other corporations to follow suit. It has been four months. No major airlines have made a similar pledge — and United Airlines is waffling.“It’s still something we are considering, but no final decisions have been made,” a spokeswoman, Leslie Scott, said.For the country’s largest companies, mandatory vaccinations would protect service workers and lower the anxiety for returning office employees. That includes those who have been vaccinated but may be reluctant to return without knowing whether their colleagues have as well. And there is a public service element: The goal of herd immunity has slipped as the pace of vaccinations has slowed.But making vaccinations mandatory could risk a backlash, and perhaps even litigation, from those who view it as an invasion of privacy and a Big Brother-like move to control the lives of employees.A United Airlines vaccine clinic at O’Hare airport in Chicago. Employers are using on-site vaccinations to encourage workers to get shots.Scott Olson/Getty ImagesIn polls, executives show a willingness to require vaccinations. In a survey of 1,339 employers conducted by Arizona State University’s College of Health Solutions and funded by the Rockefeller Foundation, 44 percent of U.S. respondents said they planned to mandate vaccinations for their companies. In a separate poll of 446 employers conducted by Willis Towers Watson, a risk-management firm, 23 percent of respondents said they were “planning or considering requiring employees to get vaccinated for them to return to the worksite.”That discrepancy, said Mara Aspinall, who led the Arizona State poll, may have to do with the timing of the surveys and the pace at which executives are growing comfortable with the vaccines. Arizona State conducted its survey in March, while Willis Towers led its survey between Feb. 23 and March 12.Despite what surveys have found, few executives have taken the step of mandating vaccines. It seems that most are hoping that encouragement, whether forceful or subtle, will be enough.“While legally in the United States, employers can mandate vaccines while providing accommodations for religious and for health reasons, socially, in terms of the social acceptability of these decisions, it’s much more tenuous,” said Laura Boudreau, a professor of public policy at Columbia University. “And so the reputational risks to these companies of getting this wrong are really high.”Douglas Brayley, an employment lawyer at the global law firm Ropes & Gray, warns clients of the implications of following through on a mandate, he said.“What if 10 percent of your work force refuses? Are you prepared to lay off that 10 percent?” he said he asked clients. “Or what if it’s someone high-level or in a key role, would you be prepared to impose consequences? And then they sometimes get more nervous.”He added, “Anytime you would have them putting out a mandate, but then carrying through the consequences unevenly, that would create a risk of potentially unlawful unfair treatment.”Companies that require vaccines may also be concerned about any side effects or medical issues that an employee might claim were caused by the vaccine.“They could be held liable for any sort of adverse effects that might happen a year or two down the road,” said Karl Minges, chair of health administration and policy at the University of New Haven.Some companies are sidestepping the problem and trying incentives instead. Amtrak is paying employees two hours’ worth of regular wages per shot upon proof of vaccination. Darden, which owns Olive Garden and other restaurants, told employees it would offer hourly employees two hours of pay for each dose they receive, while emphasizing it would not make doses mandatory. Target is offering a $5 coupon to all customers and employees who receive their vaccination at a CVS at Target location.For restaurants, making vaccinations mandatory could make hiring workers even more difficult.Philip Cheung for The New York TimesIn the United States, there’s nothing new about vaccines being required for participation in public life. The Supreme Court ruled about a century ago that states could require vaccinations for children attending public school. And universities like Rutgers have instituted mandatory Covid-19 vaccinations.But the pandemic brings up a host of complications that companies typically prefer to avoid, involving the private lives, religious preferences and medical histories of employees, such as whether an employee is pregnant, breastfeeding or immuno-compromised, information they may not want to reveal.Major union groups, like the A.F.L.-C.I.O., have not aggressively pushed the issue either. They are facing dueling forces — standing up for individual worker’s rights on the one hand and protecting one another on the other. Unions have also been arguing for stronger workplace safety measures, efforts that could be complicated by companies’ arguing that mandatory vaccinations reduce the need for such accommodations. The return to work protocols negotiated between the Alliance of Motion Picture & Television Producers and Hollywood’s unions, for instance, will not include mandatory vaccinations.“There are going to be some people who may have legitimate reasons for not getting the vaccine or for not wanting to talk about it,” said Carrie Altieri, who works in communications for IBM’s People and Culture business. “It’s not an easy issue at this point.” IBM is working with New York State on a digital passport linking a person’s vaccination records to an app to show businesses, like performance venues, that may require vaccination. It is not, though, requiring vaccinations for its employees.For some businesses like restaurants, which are already struggling to hire workers, mandating vaccinations could make hiring even more difficult. And there are questions of logistics and execution. How can companies confirm the veracity of those who say they’ve been vaccinated?Companies may need to hire additional staff, potentially with medical training, to handle such tasks, which could saddle businesses — particularly small ones — with burdensome costs.Vivint, a home security company based in Utah with 10,000 employees, began offering vaccines in its on-site clinic this week, after the state approved the company to distribute 100 shots a week to its staff. It paid $3,000 for the necessary medical-grade freezer.“We’re not requiring employees to get vaccinated, but we’re highly encouraging it,” said Starr Fowler, senior vice president for human resources. “For a lot of our employees, particularly those that are younger, the easier that we make it for them, the more likely they’re going to do it.”At Salesforce Tower park in San Francisco, up to 100 fully vaccinated employees can volunteer to work on designated floors.Jason Henry for The New York TimesOthers are experimenting with splitting up their work forces. Salesforce is introducing a policy in certain U.S. offices, including Salesforce Tower in San Francisco, where up to 100 fully vaccinated employees can volunteer to work on designated floors. The New York Stock Exchange issued a memo to trading firms saying they would be allowed to increase their staff on the floor, provided all the employees have been vaccinated.The Equal Employment Opportunity Commission issued guidance in December stating that employers were indeed legally permitted to require employees to be vaccinated before they return to offices. But the threat of litigation still looms.“To be concerned about the possibility of litigation seems to me to be a perfectly legitimate concern,” said Eric Feldman, a law professor at the University of Pennsylvania. He added, “It would seem to me that employers are going to find themselves in a fairly strong position legally — but that doesn’t mean they’re not going to get sued.”Legislation that would limit the ability to require vaccines for students, employees or the public in general has been proposed in at least 25 states, according to the National Conference of State Legislatures. Some of those restrictions pertain only to vaccines that, like those for Covid-19, have yet to be granted full approval by the Food and Drug Administration. (The coronavirus vaccines have been granted conditional approval for emergency use.)Pfizer is expected to file for full approval of its Covid-19 vaccine soon. Others are expected to follow.Speaking at a Wall Street Journal conference this week, Jamie Dimon, the chief executive of JPMorgan Chase, mentioned “legal issues about requiring vaccines” when asked about bringing workers back to the office. A press officer for the bank, which plans to open its offices on May 17 on a voluntary basis, said it strongly encouraged vaccines for employees — barring any religious or health restrictions — but would not require them. A spokeswoman for Goldman Sachs, which has not guided employees either way, declined to comment.One potential path for companies seeking a middle ground is to mandate the shots only for new hires. Still, there is a fine line between encouraging and requiring shots — sometimes resulting in conflicting messages to employees.The investment bank Jefferies sent a memo to employees in early February stating “verification of vaccination will be required to access the office.” On Feb. 24 came a follow-up memo. “We did not intend to make it sound as if we are mandating vaccines,” it said.Reporting was contributed by