The world is on high alert with the latest developments of the Covid-19 omicron variant, which the World Health Organization said Monday poses a "very high" global risk. On Wednesday, U.S. health officials confirmed the country's first case of the variant in California.

U.S. business leaders, meanwhile, are scrambling to figure out how the omicron variant could impact their workplaces, and what health and safety measures they can use to get ahead of it, says Dr. Neal Mills, chief medical officer for professional services firm Aon.

Here's how he and other health experts are advising business leaders to navigate the latest Covid variant.

What we know about the omicron variant

There are still a lot of unknowns about omicron as researchers study its transmissibility, severity and whether vaccinations will stand up to the variant.

But there's some good news: Nearly two years into the pandemic, we know a lot more about Covid-19, how to prevent it and how to treat it.

Some of the best efforts at containing the virus and its variants have remained constant throughout, says Dr. David Levy, CEO of the preventive health company EHE. That includes getting vaccinated, wearing a mask indoors and social distancing in areas of high transmission, as well as getting tested regularly to keep the virus from spreading to other people.

Workplaces can do their part in all three efforts, including helping workers get vaccinated and providing paid time off to do so, providing employees face coverings and space to social distance indoors, and paying for regular testing for people to report to work.

Levy doesn't see omicron as "a cause for panic," but does stress the need for everyone, including businesses, to keep their guard up and do everything they can to minimize its impact.

We're better prepared from the delta variant

Dr. Denis Nash, a professor of epidemiology at the CUNY Graduate School of Public Health, says we can also learn from how we handled, or didn't handle, the delta variant as it spread through the U.S. over the summer.

"In the U.S., the CDC leadership and Biden administration didn't seem to anticipate that delta would become what it did, even though we saw it spread in the U.K. and around the world," Nash says. "Now, we're a little more prepared due to genomic surveillance happening elsewhere in the world."

Over the summer, in response to the delta surge, the CDC reinstated its guidance for everyone, including fully vaccinated people, to wear masks in indoor public settings in areas of high transmission. Shortly after, the Biden administration announced it would require all civilian federal workers to get vaccinated.

Many of today's workplace policies around health and safety, vaccines and testing are a direct result of responding to the delta variant, Levy says. With the latest variant and delta still circulating widely, he adds that workplaces might consider re-instating contact tracing for employees who test positive for Covid and creating travel advisories in areas of high transmission.

There could be more worker vaccine requirements

One of the broadest standards to come out of the rise in cases over the summer is the federal vaccine mandate, governed by the Occupational Safety and Health Administration, which requires employees of all private-sector companies with 100 or more workers be fully vaccinated by Jan. 4.

The rule is estimated to cover more than 84 million workers — 31 million who were not yet vaccinated as of early November — and two-thirds of the nation's private-sector workforce. Roughly 71% of American adults are fully vaccinated as of Dec. 1, according to the CDC.

Next, employers not covered under the federal OSHA rule, such as state government offices or schools, could create their own vaccine requirement, Levy says, especially if cases climb in the winter.

Booster shots aren't currently required under the OSHA rule, but it could become the standard for an employee to be considered fully vaccinated to report to the workplace.

Employers might require regular Covid testing, regardless of vaccination status

While advising businesses on return-to-office plans over the summer, Mills says many employers were "shocked" at the high price of having workers regularly tested in order to return safely. "The costs were so staggering that many realized it was a luxury they simply couldn't afford."

But more affordable options could be coming to market. In the last month, the U.S. Food and Drug Administration updated its authorization policy to increase access to at-home Covid tests, which could give Americans access to 400 million more over-the-counter tests each month by early 2022.

As testing options become more accessible, more employers might require workers to regularly test themselves at home, at a health center near work, or at the workplace itself regardless of vaccination status in an effort to slow asymptomatic spread.

Return to offices could be pushed again, but we won't have a clear idea for a few weeks

Just as the delta variant pushed Labor Day 2021 return-to-office plans back, the omicron variant could delay those plans further into 2022.

Companies may push reopening dates if scientists find the vaccines aren't as effective at preventing severe illness caused by omicron, Nash says. On the other hand, "I can also envision a scenario where we learn in the coming weeks that vaccines remain protective against severe disease and death with the variant, which doesn't set the timeline back," he says.

Whatever happens, Nash says leaders should communicate to employees that they understand uncertainty can cause anxiety, but they're taking steps to stay up-to-date on the latest information to guide any new Covid safety plans.

Check out:

Covid’s omicron variant poses a ‘very high’ risk — here’s what you need to know right now

Your Covid booster side effects shouldn't be as 'intense' this time — here's what to expect

For many workers, the return to offices has become ‘The Great Wait.’ It’s costing employers millions

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