Increasingly tough employers include the federal government, the state governments of California and New York, tech giants Google and Facebook, Walt Disney Co., and the NFL. Some hospitals, universities, restaurants, bars and other places of entertainment have also started requiring vaccines.

But the new measures are unlikely to affect most of the millions of unvaccinated Americans.

Most businesses that require vaccines mostly have office workers who are already widely vaccinated and are reluctant to work alongside those who are not.

By contrast, large companies that rely on low-income blue-collar workers – food manufacturers, warehouses, supermarkets and other chain stores – are shying away from mandates for fear of firing employees and exacerbating labor shortages. work that these companies are facing.

Tyson Foods, for example, said about half of its U.S. workforce – 56,000 employees – received injections after the meat and poultry processor held more than 100 vaccination events since February. But the company said it had no plans to impose a warrant to reach the other half.

Walmart and Amazon, the country’s two largest private employers, have also refused to require their hourly workers to get vaccinated, continuing to rely on strategies such as bonuses and on-site access to vaccines. But in a potentially powerful signal, Walmart said employees at its head office will need to be vaccinated by October 4.

The greatest precedent to date has come from the federal government, the country’s largest employer. President Joe Biden announced last week that all federal employees and contractors must get vaccinated or have weekly tests and lose privileges such as official travel.

The federal government has said it will cover the costs of the weekly tests. As with other employers, insurance may pay for such tests in some workplaces but not in others.

Biden’s move could embolden other employers by signaling that they would be on a solid legal footing to impose similar rules, said Brian Kropp, head of research at the human resources practice at consulting firm Gartner.

But Kropp said some companies face complicated considerations that go beyond the legalities, including deep resistance to vaccines in many states where they operate.

Retailers like Walmart might find it difficult to justify vaccine requirements for their employees while allowing shoppers to remain unvaccinated, Kropp added. Stores have mostly avoided vaccine requirements for customers for fear of alienating them and the difficulty of trying to verify their status.

In Gartner polls, less than 10% of employers said they intended to require all employees to be vaccinated.

But a change is occurring amid frustration over the cap on vaccination rates and alarm bells over the spread of the most contagious delta variant.

On Monday, the United States finally met Biden’s target of dispensing at least one injection to 70% of American adults – but with a month late and amid a surge that is pushing the number of cases in hospitals at their highest level since the start of the epidemic. The president had hoped to achieve his goal by July 4.

The Union Square Hospitality Group, a New York restaurant and bar group founded by Danny Meyer, now requires employees and customers to be vaccinated by September 7.

The San Francisco Bar Owner Alliance, a group of about 300 bars, made a similar decision following a meeting where “the thing that stood out was anger and frustration” with people who resist vaccines. , said founder Ben Bleiman.

While some companies fear that vaccination warrants will scare workers away, the pandemic itself is also causing absenteeism. Bleiman said he was recently forced to shut his bar overnight after his bartender, who was fully vaccinated, tested positive and no replacement could be found.

Some employers conclude that it is simpler to require vaccines than to try to develop different rules on masks and social distancing for the small number of unvaccinated employees.

BlackRock, the global investment manager, is currently only allowing vaccinated workers in its US offices and has said people will be free to do without masks, as local health guidelines allow, and to wear masks. sit next to each other and gather without restrictions. The company said 85% of its U.S. employees are vaccinated or in the process of being vaccinated.

Matthew Putman, CEO of New York-based high-tech manufacturing center Nanotronics, said he was distressed by his decision to impose a vaccine mandate on its more than 100 employees. It turned out that almost all of them were already vaccinated, although he dreaded the prospect of having to fire holdouts.

“I hate the idea. But if it’s going to happen, it has to happen, ”Putman said. “I lost a ton of sleep because of it, but not as much sleep as I lost because of the fear of infection.”

Other mandates could provide a clearer test of employee reaction potential.

Hospitals and nursing home chains, for example, are increasingly demanding the vaccine. So far, these warrants have survived legal challenges. More than 150 employees at a Houston hospital system who refused to be vaccinated against COVID-19 were fired or resigned after a judge dismissed a lawsuit against an employee for the requirement.

Atria Senior Living, which operates more than 200 senior citizens’ residences across the country, was among the first to impose vaccines on its staff in January.

It worked. Almost 99% of Atria’s 10,000 employees are vaccinated, and only a tiny fraction have resigned from the requirement, said CEO and Chairman John Moore.

“Our residents deserve to live in a vaccinated environment. Our staff deserve to work in a vaccinated environment, ”said Moore.

Associated Press Business Writers Anne D’Innocenzio and Dee-Ann Durbin contributed to this story.