Some businesses and workers are likely to challenge the orders in court, but many more companies will “appreciate having the cover,” said Dorit Reiss, a professor at the University of California Hastings College of the Law who has studied vaccine mandates for nearly a decade.

“It helps them increase vaccine rates and they can blame the government,” she said. “Vaccine mandates work because for most people, even if they have a position against it, it’s not strong enough to sacrifice their jobs.”

Those who don’t work for federal contractors and are afraid of the vaccine can choose weekly testing instead, but Reiss said many people who are simply hesitant are more likely to get immunized.

“The testing is sufficiently burdensome that most of them would prefer just to be vaccinated,” she said.