US workers could soon face choices such as free Covid-19 shots and a cash bonus if all get immunised, or those unwilling to be vaccinated get reassigned or even lose their jobs.

Those options are being studied by businesses hoping to bring at-home employees back without triggering a backlash or violating federal and state employment law. Companies are consulting lawyers, health care experts and polling their workers to gauge when to offer carrots and when to use a stick.

Workplace programmes could come following US approval of the first vaccine this week. But the array of choices reflects huge hurdles. A Pew Research poll shows 21 per cent of Americans are firmly opposed, with 60 per cent likely to get a shot. That split, and worries about side effects, have led to a wide variety of potential options.

“Some of my clients say ‘if you get a vaccine, we’ll give you a bonus,’” said Rogge Dunn, who runs a Dallas law practice and is advising businesses on setting up programmes to encourage workers to get inoculated.

Employees may not be easily swayed.

“All this rushing has me nervous,” said a registered nurse in Georgia, who insisted no incentive would change her mind. She spoke on condition of anonymity and believes the fast pace of development raises the risk of neurological problems.

There have been few serious side effects in large trials of the Pfizer and Moderna vaccines and no publicly reported evidence of a link to neurological problems. A panel of outside advisers to the US Food and Drug Administration on Thursday voted that benefits outweigh the risks with Pfizer’s vaccine.

Other workers say they will freely line up for shots once the rollout to health care workers proves successful.

“I’m willing to take it, but not maybe immediately,” said Sean Rollins, a 37-year-old Massachusetts carpenter who wants to see if serious side effects emerge. Protecting his family is more important than any incentive, but free would be nice.

“I want to get it as soon as possible. No incentive necessary,” said Alissa Gabriel, 51, a San Diego, California, municipal worker, who believes the vaccines will help workers return to their office towers from remote work.

Among big employers starting to formulate policies are oil giant Chevron Corp, auto maker Ford Motor Co, retailer Target Corp, restaurant chain Ford’s Garage, the United Steelworkers union, and refiners’ Marathon Petroleum and Citgo Petroleum.

Their efforts are preliminary given FDA vaccine approvals remain outstanding.

Private employers could set up mandatory vaccinations so long as they offer accommodations to workers with religious and medical conditions that would exempt them, said Sarah Mitchell Montgomery, a partner at Jackson Walker LLP advising corporate clients. The direct threat posed by the Covid-19 pandemic will allow mandatory programmes to win approvals soon, she believes.

“There may be situations where there is not a good accommodation,” such as allowing those employees to continue to work from home, wear protective clothing or equipment on the job, she said. To protect workers from unvaccinated employees, companies also could argue they need to remove recalcitrant staff to protect others, she said.

Marathon Petroleum, the largest US oil refiner, “is developing plans for its use of COVID vaccines,” said spokesman Jamal Kheiry. Policies for its 60,000-person workforce are still being formulated, he said.

Target, which has more than 1,700 retail stores with in-house pharmacies, said it plans to use those health care outlets to offer authorised vaccines to store workers and shoppers as supplies become available.

Ford Motor ordered freezers to be able to store vaccines and begin a voluntary immunisation programme when supplies allow. General Motors and Fiat Chrysler Automobiles also are weighing internal programmes.

Vaccination programmes, exemptions and access are being studied by union officials. The United Steelworkers union, which represents teachers, healthcare, mining, petrochemical and government workers, is looking to the CDC for recommendations. But it is concerned about workers being told to get vaccinated.

“Vaccination should be strongly encouraged,” said Michael Wright, USW director of health, safety and environment, but not mandatory. Workers who develop side effects should receive free health care and be paid for time out of work, he said.