We’ve been following the legal challenges to the Biden administration’s vaccine rule, which stipulates that companies with 100 or more employees require COVID vaccinations or weekly tests.

A U.S. Court of Appeals temporarily blocked the rule over the weekend. The Justice Department argues it will protect workers. But in the meantime, many businesses are preparing anyway.

Companies have a lot of work to do to comply with the rule by Jan. 4, 2022.

“There’s a lot of processes and paperwork that they have to pull together, they have to communicate with their employees about this,” said Karen Kerrigan, the CEO of the Small Business and Entrepreneurship Council.

That work can be costly, she said — especially for smaller companies with 100 or 200 employees. Still, Kerrigan is advising businesses to prepare early, since they could face fines if they don’t comply.

“And that’s why many of them are moving on it, regardless of what might happen from a legal perspective,” she said.

Many companies want their workers to be vaccinated but haven’t wanted to enforce it, according to Evan Rawley, a professor at the University of Connecticut.

“They feel like, ‘Gee, some of our employees might be unhappy if we mandate this, and we don’t want to have a lot of blowback from the rank and file,’ or there might even be senior executives who are opposed to it,” he said.

Complying allows companies to tell employees they’re just following the rules, Rawley added.