It could work because evidence this far shows workers would rather get the vaccine than deal with burdens they consider onerous at work, said Lawrence Gostin, a professor of global health law at Georgetown University Law School.
"People would much rather roll up their sleeves and get a jab, than undergo weekly testing and universal masking," he said. "In many ways, this is really not a mandate, it's giving workers a choice."
About 60 per cent of American adults have been fully vaccinated. Biden had set a July 4 goal to get at least one shot in 70 per cent of adults, and is still not quite there. The latest figure is 69.3.
According to the Office of Personnel Management, the executive branch employed more than 2.7 million civilians in 2020, with some of the most significant numbers in Republican-led Southern states including Texas and Florida, where substantial vaccine resistance remains.
But the move is not just about federal workers.
The administration hopes it will nudge private companies push their workers harder to get vaccines that, while widely recognised as safe and effective, have yet to receive full approval from the Food and Drug Administration.
"I think we've reached this tipping point, and Biden's announcement will provide a lot of air cover for companies and boards of directors who have difficult decisions facing them," said Jeff Hyman, a Chicago-based business author and recruiter for start-up companies.
Employers want to get their workers vaccinated but have been holding back, said Andrew Challenger, senior vice president of Challenger, Gray & Christmas, a major workforce consulting firm.
"It is a large risk over the head of every employer if there is an outbreak at the office," he said. "But so far we have seen very few employers using a stick instead of carrots."
Gostin agrees: "We've begged, pleaded, cajoled people to be vaccinated; we've offered them incentives, and it's clear that that is not working."
Some of the nation's biggest corporations have moved to require vaccinations for their workers. Tech giants Facebook and Google announced this week their employees would have to show proof they've been fully vaccinated before returning to work.
Delta and United airlines are requiring new employees to show proof of vaccination. Goldman Sachs and Morgan Stanley are requiring workers to disclose their vaccination status though not requiring them to be vaccinated.
But fewer than 10 per cent of employers have said they intend to require all employees to be vaccinated, based on periodic surveys by the research firm Gartner.
The Biden administration hopes its federal-worker guidance will help change that, by providing a model for state and local governments and private businesses to follow as workers prepare to return to offices this fall.
Many companies — particularly smaller ones concerned about legal ramifications — could take the guidance as "justification for implementing similar policies," said Alexander Bick, an associate professor of economics at the WP Carey School of Business at Arizona State University.
Questions about the new policy's scope remain.
The guidance is not expected to cover the military, but it's unclear if it will cover federal contractors. The White House hopes that releasing the new guidelines now will give agencies enough time to craft their own plans for implementation before workers return fully to offices.
And there is already opposition.
State lawmakers across the US have introduced more than 100 bills aiming to prohibit employers from requiring vaccination as a condition of employment, according to the National Academy for State Health Policy. At least six states have approved such bills.
The Justice Department and the federal Equal Employment Opportunity Commission have both said no federal laws prevent businesses from requiring vaccinations as a condition of employment and the federal policy would take precedent. But the "medical freedom" bills underscore the resistance such guidance may encounter at the state level.
Government actions in New York City and California have already faced resistance from local unions. And prior to Biden's announcement, some national unions were speaking out against it.
Brian Rothenberg, spokesman for the 397,000-member United Auto Workers, said the union encourages workers to get vaccinated but is against requirements because some people have religious or health concerns.
Larry Cosme, President of the Federal Law Enforcement Officers Association, which represents 30,000 federal officers and agents, said in a statement while the organisation supports the vaccine it opposes compelling it.
"Forcing people to undertake a medical procedure is not the American way and is a clear civil rights violation no matter how proponents may seek to justify it," he said.
