COLUMBIA, S.C. (AP) — The operator of a sprawling federal nuclear reservation in South Carolina says the vast majority of its 5,500 workers are now vaccinated against COVID-19 after the company mandated the shots.

But nearly 80 Savannah River Site employees who have refused to get inoculated are now suing Savannah River Nuclear Solutions over the requirement, arguing the stipulation amounts to illegally practicing medicine and therefore breaks South Carolina law.

In a complaint filed Thursday in South Carolina state court, the workers said they wanted a judge to stop the federal contractor from instituting the mandate, which requires employees to get vaccinated against the highly contagious virus or face firing.

The mandate was issued in early September, a few days before President Joe Biden's order that all larger businesses require their employees be vaccinated against COVID-19.

The lawsuit states the company is compelling workers to get their first shot by Oct. 15. The complaint argues that mandate "constitutes the illegal practice of medicine" and says it violates the state's public policy, which "always gives South Carolinians the choice in refusing to take a vaccine without being punished as a result of that medical choice."

A total of 114 nuclear workers at Los Alamos National Laboratory in New Mexico have also sued ahead of the Friday vaccine deadline set by that lab's contractor. Among them are scientists and other specialists who some employees say could be difficult to replace in the short term if fired.

The South Carolina workers skeptical of the vaccine's efficacy and safety appear to represent a small fraction of those employed by Savannah River Nuclear Solutions, which has held a U.S. Department of Energy contract to manage and operate the old nuclear weapons complex south of Aiken since 2008.

About 95% of Savannah River Nuclear Solutions' 5,500 workers have been vaccinated so far, according to spokesperson Barbara Smoak. The company's mandate is aimed at protecting the health and safety of its workforce, she added.

"It is SRNS' sincere desire that those who are unvaccinated will decide to receive the vaccine prior to the Nov. 30 deadline for full vaccination and remain employed by SRNS," Smoak said in a Thursday statement.

Smoak didn't elaborate on whether, or how many, unvaccinated workers would be terminated following Friday's deadline in light of the litigation.

Some workers had previously told WJBF-TV that the company has denied submitted religious and medical exemptions.

Donald Brown, Jr., an attorney for the workers, told The Associated Press that anxiety is high among unvaccinated workers, many of whom have highly specialized positions and could have a hard time finding new jobs: "It's not like you can go over to the town next door and find another nuclear contractor," Brown said.

Medical experts have said vaccines are safe and highly effective in reducing the spread of COVID-19, which has claimed the lives of more than 13,000 South Carolinians.

The state Senate unanimously passed a bill in April preventing employers in South Carolina from mandating COVID-19 vaccines for workers with exceptions like health care workers or employees who deal with vulnerable populations. But the proposal never became law and ended the 2021 session in a House committee.

Some South Carolina Republicans have since vowed to fight the federal order.

In Texas, Gov. Greg Abbott recently issued an executive order preventing businesses from requiring vaccines. But South Carolina Gov. Henry McMaster has indicated that he wouldn't do the same.

"I think Gov. Abbott is a very experienced leader in Texas, but in our state, we didn't tell our businesses what to do, and we're not going to tell them what not to do," McMaster told reporters Tuesday.


Associated Press reporter Jeffrey Collins contributed to this report.