From Walt Disney World and Chevron to CVS and a Michigan university, a flurry of private and public employers are requiring workers to get vaccinated after the federal government gave full approval to Pfizer’s COVID-19 vaccine. And the number is certain to grow much higher.

For the past eight months, the coronavirus shot was dispensed in the U.S. under emergency authorization from the Food and Drug Administration. Some workers and unions objected to getting the vaccine — and some employers were reluctant to require it — because it had yet to receive FDA full approval. That happened on Monday.

“The FDA decision takes that off the table,” said Devjani Mishra, a New York-based attorney with the firm Littler Mendelson, which specializes in workplace matters. She and others in the worlds of business, law and health predicted more companies will mandate vaccines for their workforces.

Shortly after the FDA acted, Walt Disney World reached a deal with its unions to require all workers at its theme park in Orlando, Florida, to be vaccinated.

Drugstore chain CVS said employees who have contact with customers will have to be inoculated. Oil giant Chevron Corp. said it will require some of its workers — such as those who travel internationally, live abroad or work on its offshore platforms in the Gulf of Mexico — to get their COVID-19 shots.

“We pushed `go’ when the FDA made that decision,” said Ora Hirsch Pescovitz, president of Oakland University in Rochester, Michigan, which announced on Monday that its 800 faculty members, 1,500 staff members and 18,000 students will have to be vaccinated. Before that, only students living on campus had to get the shot.

She said the university could have legally mandated vaccines before the FDA decision but waited for it because Pescovitz, who is a pediatrician, believes the authorization would help persuade those still on the fence.

On Monday, health experts expressed hope that the FDA’s action would boost the U.S. vaccination rate, which bottomed out at about a half-million shots a day in July — down from a peak of 3.4 million a day on average in April.

The number of shots dispensed has since climbed to about 850,000 a day amid growing alarm over the highly contagious delta variant, which has sent deaths, cases and hospitalizations soaring, wiping out months of progress.

Littler Mendelson released a survey Monday showing that 9% of employers are already mandating vaccines for at least some of their workers, and an additional 12% are planning to impose some sort of mandate in the near future. In January, just 1% of firms Littler Mendelson surveyed had issued vaccine requirements.

There is a risk for employers at a time when many are struggling to fill openings and workers are confident of finding better jobs: Faced with a vaccine requirement, an employee might “say, ‘OK, fine. I’m leaving,’” Mishra said. “It’s not a given you’re going to be able to fill that job with someone who is vaccinated.”

But Ali Mokdad, a professor of health metrics sciences at the University of Washington in Seattle, said he doesn’t foresee a large backlash.

“People will see that mandates can open their businesses and save their paychecks. They will see the effects and they will welcome it,” he said.

Earlier this summer, President Joe Biden announced that federal workers will have to get vaccinated or else face weekly testing and other measures.

The nation’s two largest private employers don’t seem to be budging. Walmart said today there is no change to its policy, which requires vaccinations for office workers but not store employees. And Amazon, which doesn’t mandate vaccines for any of its employees, did not respond to a request for comment.

As for the auto industry, Ford Motor Co. said it is not requiring the vaccine, and General Motors has said it isn’t either, though CEO Mary Barra has held open the possibility.

The career-advice website Ladders Inc. released a study last week showing a more than 50-fold increase since January in job openings that require applicants to be vaccinated.

Ladders spokeswoman Laurie Monteforte predicted vaccine requirements will only rise after the FDA decision. Many employers, she said, have exhausted vaccine incentives such as bonuses or other perks.

Employers that require vaccines are on solid legal ground. Private companies and government employers can generally require workers to be inoculated as a condition of working there, though they must offer exemptions or accommodations in some cases.