People shout anti-government slogans as they arrive at City Hall on October 25, 2021 in New York City to protest the COVID-19 vaccine mandate.

Eduardo Munoz | Reuters

According to a survey published by the Kaiser Family Foundation on Thursday, five percent of unvaccinated adults state that they have given up their jobs because of a vaccination mandate.

This early reading of whether employees will actually quit their jobs through mandates comes as more and more employers need injections. A quarter of workers surveyed by KFF in October said their employer required them to get vaccinated, up from 9% in June and 19% last month.

President Joe Biden announced a mandate for companies with 100 or more employees in September to ensure workers are vaccinated against Covid or tested for the virus weekly. The mandate, which is currently still under review, is expected to cover around two thirds of private sector employees once it is implemented. The Kaiser survey only asked whether people had stopped because they needed a vaccine, not a mandatory vaccination with a test option.

More than a third of unvaccinated workers said they would rather quit than comply with a vaccine or test mandate, the Kaiser survey shows, a proportion that climbs to 72% if no test option is offered. However, as the state-wide mandate has yet to be officially implemented by the Department of Labor, it remains to be seen what proportion of workers will quit when a wider segment of the US workforce is included.

“Right now, only a quarter of workers say their employer asked them to get a vaccine. Still, according to Lopes, the survey results give “a sense of people’s attitudes” about the requirements.

Already mandated workers are more likely to have higher household incomes, identify themselves as Democrats, and are already vaccinated, the data shows. The poll results also illustrate the ongoing partisan split over Covid-19 vaccines: 32% of Republican respondents say they know someone who quit because of a mandate, compared to 14% of Democrats who said the same thing.

Kaiser interviewed 1,519 randomly selected American adults from October 14 through October 24.

US corporate groups have opposed the upcoming mandate and asked the White House to postpone the rule until after Christmas time.

“We are totally in favor of the vaccine, we distributed the vaccine, we spent millions creating incentives for employees to get the vaccine,” said Ed Egee, who works for the National Retail Federation for Government Relations and Human Resources Association of retail. However, Egee said engaging employers in a discussion that was “controversial and political” would create significant implementation challenges and risk the potential of vacation staffing shortages.

The NRF has asked the White House for a 90-day implementation period after the rule is completed, Egee said, in order to have time to review staff vaccination status, review exemption requests, and develop plans for weekly testing.

When asked about survey data suggesting that a small proportion of adults left their jobs because of mandate, Egee noted that there are likely to be significant geographic differences behind the national numbers. Employers in the south and mountain west are likely to see higher levels of worker resistance, he said.

The National Manufacturers Association said in a letter to the federal government last week that the loss of even a small fraction of workers could have significant ramifications for some of its member companies.

“Especially in small companies with barely more than 100 employees, the departure of even a highly valued team member can lead to production challenges if it is not appropriately managed or planned,” writes Robyn Boerstling, a top lobbyist for the manufacturer group. “For larger companies, even losing 1% of a production team could have operational consequences as a skilled worker specializes in manufacturing.”

An internal survey by the American Trucking Associations estimates that mandated haulage companies would lose approximately 74% of unvaccinated employees, or 37% of their total workforce, to retirement, firing, or moving employees to smaller, non-mandated companies. However, this survey assumes that the proportion of respondents who said they would stop will in due course, the trading group said in a letter sent to the Office of Management and Budget last Thursday that the rule for whites checked house.

When asked if the drivers are actually leaving the company, Jeremy Kirkpatrick, the association’s director of strategic communications, said it was too early to say as the rule has not yet been published.

“We’re in a wait and see mode right now,” Kirkpatrick wrote in an email to CNBC.

The Kaiser survey also shows that most unvaccinated workers would not quit immediately if faced with a mandate. About six in ten said they would likely apply for a religious, medical, or other exemption if their employer asked them to get a vaccine.

“There are many options that people would try before they quit a job,” said Lopes, the KFF analyst.

Nearly 58% of the total US population is fully vaccinated, including nearly 70% of adults, according to the Centers for Disease Control and Prevention.

CNBC’s Spencer Kimball contributed to this report.