As the vaccine rollout continues across the country, employers are wondering if they can mandate shots for their workers. In the healthcare field where workers have been given top vaccine priority, this question has already caused legal battles.

According to ABC News, first responders in New Mexico filed a lawsuit after a county official ordered firefighters, correction officers, and other first responders to get vaccinated. In Wisconsin, 21 employees at the Rock Haven Nursing Home quit after being issued a vaccine mandate. Fifteen of the employees are threatening legal action and their attorney, Michael Anderson said that while some of his clients did get the shot, “they felt coerced to do so.”

Vaccine hesitancy is common among nursing home workers, according to a report from the Centers for Disease Control and Prevention that found 62% will not get the vaccine, says ABC News.

Statistics show that since the government prioritized the vaccination of residents in nursing homes, there has been a significant decrease in the number of serious illness and death from COVID-19. However, experts say that because none of the three vaccines now available have received full approval from the Food and Drug Administration, it would be unusual for employers to mandate their use.

The Pfizer, Moderna, and Johnson & Johnson vaccines have been granted emergency authorization by the FDA. Mike Wasserman, of the Vaccine Advisory Committee in California, told ABC News he believes “it is unethical to require a treatment that was approved under an emergency authorization.” Rather, he said, it would be best for employers to give employees incentives to get vaccinated.

Jennifer Miller, Ph.D., an assistant professor at Yale School of Medicine and founder of the nonprofit Bioethics International, disagrees, arguing that the urgency of containing COVID-19 justifies mandating vaccination.

“We have an ethical obligation to try and pursue behaviors that will not expose others to COVID risks,” she said, adding that getting vaccinated is one such behavior.

Dorit Reiss, a law professor at the University of California, who specializes in legal and policy issues related to vaccines, tells AARP that “employment in the United States is generally ‘at will,’ which means  that your employer can set working conditions.”

However, if employees have deep seated religious convictions or medical reasons why they do not want to get the COVID-19 vaccine, Reiss says that employers could be legally required to offer alternatives such as wearing a mask or working remotely.

“If you can achieve the same level of safety as the vaccine via mask, or remote working, you can’t fire the employee. You need to give them an accommodation,” he says.

Attorney Matt Murphy told ABC News that under the Americans with Disabilities Act, it is legal for employers to mandate vaccines in their workplace, but he added,

“I think we’re going to see endless litigation over this issue.”