As California studies whether to create a statewide system that would verify who has been vaccinated against COVID-19, Santa Clara County officials forged ahead Tuesday with a new requirement that employers find out which of their workers have gotten their shots.

The South Bay county’s rule, which appears to be the first of its kind in the Bay Area and possibly the Golden State, could free vaccinated employees from requirements to wear masks and socially distance the workplace. And it would require employers to treat workers who refuse to say whether they’ve had a shot as though they haven’t.

What happens next depends on California’s Division of Occupational Safety and Health, which is considering policy changes at a meeting Thursday that would let vaccinated workers drop those precautions, while workers who aren’t inoculated would be expected to keep them up. The state and the nation have been moving to allow greater privileges for those who are fully protected, but officials have not detailed how they expect everyone from bosses to bartenders to figure out the vaccination status of the people they’re interacting with.

The proposed new state workplace policies “very clearly differentiate between what’s required in the workplace in terms of safety rules for those who are fully vaccinated and those who are not,” Santa Clara County Counsel James Williams said at a news conference Tuesday.

“That’s why it’s all the more important,” Williams said, “for businesses to know the vaccination status of their workers.”

Federal guidelines announced last week allow the fully vaccinated — those who are two weeks past their final shot — to forgo masks outdoors and in most indoor settings, such as at stores or offices. California said it will adopt those guidelines on June 15, when the state plans to drop most pandemic restrictions, now that 15.8 million residents are fully vaccinated against COVID-19 and another 4.7 million are at least partially inoculated.

State Health and Human Services Secretary Dr. Mark Ghaly said Monday that California is using the next four weeks to allow more people to get fully protected and to see how those federal rules play out across the country. State officials are also considering how various technologies such as mobile phone apps that can quickly show proof of vaccination might play into the reopening and lifting of mask rules for the vaccinated, Ghaly said, though he would not say if the state will require them.

“There are different ways to implement” such a system, he said, “and this gives California some time to do that in a way that allows us to do it well without a level of confusion.”

“Vaccine passport” apps have already been employed by private airlines, sports venues and New York state, though critics have raised concerns about privacy and fairness to those who can’t afford or lack access to the technology.

The company CLEAR’s Health Pass app has been used by United and Delta airlines to verify COVID-19 test results and vaccination for travelers to Hawaii, by Major League Baseball teams such as the San Francisco Giants for ballpark entry, and by Walmart, which has partnered with the company. The International Air Transport Association’s Travel Pass app is being used for international travelers.

New York partnered with IBM to create the first state vaccine passport app, Excelsior Pass, in March. The free, state-funded app has been used to confirm COVID-19 test results and vaccination at sporting and performing arts events.

But some states, including Florida, have made it illegal to ask for people’s vaccination status in businesses and government agencies. And others have put the onus on individual companies to find out whether patrons and staff are vaccinated.

In a poll released Tuesday from UC Berkeley’s Institute for Governmental Studies, 63% of Californians said they were OK with having to show proof of vaccination or a negative coronavirus test to get into sporting events, concerts or other activities. But residents were less sure about a government vaccine verification system — 35% said they thought the government should set up a “uniform verification system” for vaccinations, while 32% said it should play only a limited role, and 26% said it shouldn’t be involved at all.

Even with a few extra weeks to study vaccine verification, Dr. Kirsten Bibbins-Domingo, a UC San Francisco epidemiologist, was skeptical that California would be able to get such a system up and running by June 15.

The result could be that businesses in many cases will have to take patrons’ word for it when they say they are vaccinated, while higher-risk gatherings, such as big sporting events or concerts, could require people to show proof. That may make some people uncomfortable, but Bibbins-Domingo said it may be good enough so long as the pandemic continues its decline.

“If the vaccination rates get sufficiently high, and the case rates get sufficiently low, then relying on the honor system — which won’t be perfect — won’t pose a large-scale threat,” Bibbins-Domingo said.

Given the challenges of vaccine verification, regularly visited places such as retail and grocery stores could decide to keep pandemic-related rules like mask requirements in place. Karin Cogbill, a labor and employment lawyer with Hopkins & Carley in San Jose, said that employers are protected from liability if they are following federal, state and local rules but would likely err on the side of caution to protect workers and customers.

“I suspect that businesses will be slower to adopt no-mask policies until their workforce is comfortable being in a workplace where people aren’t wearing masks,” Cogbill said. “I could see businesses deciding that administratively it’s easier to keep mask mandates in place.”

One Oakland bar isn’t planning on using the honor system: When Eli’s Mile High Club reopens on Friday for the first time since last winter’s COVID-19 surge, it will require patrons to show their vaccination cards at the door.

Co-owner Billy Agan said the move is meant to protect the bar’s staff and to provide peace of mind for vaccinated patrons, who may feel hesitant about returning to the kinds of activities they have spent more than a year avoiding because those activities posed too great of a coronavirus risk.

“I don’t think people will feel safe with the honor system,” Agan said. “I want to create a space where people can feel comfortable in public again.”