Originally Published: 16 NOV 21 11:33 ET

By Alicia Wallace, CNN Business

(CNN) -- In the search for workers in this tight labor market, companies have courted new hires with the promise of higher wages, sign-on bonuses, ample vacation time, and childcare.

The latest: "No vaccine required."

That three-word phrase is popping up across online job listings (sometimes emphatically in all caps and accompanied by exclamation marks) as businesses seek to turn the federal government's proposed vaccine decree on its head and attract employees -- notably those from a talent pool that's been turned off by or turned away from employers that require a Covid-19 vaccination.

Under the series of federal regulations, which have met some legal challenges that could delay or stop their implementation, private businesses with more than 100 employees, certain health care workers and federal contractors will be required to be fully vaccinated or, in some cases, undergo regular testing for the Covid-19 virus.

And although the reasons behind the "no vaccine required" job listings vary by business — for some owners, it's philosophical; for others, it's desperation amid an unbalanced labor market — several employers say it's working.

When Primal Life Organics amended its job postings to include the phrasing "NO VACCINE REQUIRED," the company saw an increase in applications from the single-digits to 30 or 40, said CEO Trina Felber, who founded the Akron, Ohio-based maker of natural skincare and dental products in 2009.

"It was at that point that we were then able to start hiring people," Felber said, noting the company brought on six new employees after adding "no vaccine required" to its job listing.

Felber said she saw an opportunity to attract employees that would fit well with the company's culture.

"We try to foster independence," she said. "I feel that as a culture for my company, I don't want people to be hired being told what they can and can't do personally. I believe that the right to choose and the freedom of choice is a basic need that every human has."

Primal Life's "no vaccine required" amendment did come with a caveat that any company policy related to the virus or vaccine could be altered "should the environment, mandates, or virus existence [change]."

However, some economists and legal experts caution that offering this particular incentive is a considerable -- and a potentially deadly -- gamble.

"My suspicion is that these employers are probably facing hiring challenges, and they're throwing everything at the wall to try to get the workers they need," said AnnElizabeth Konkel, an economist at the Indeed Hiring Lab. "That's a very short-term bet with long-term consequences."

On Indeed's job listing site, the "no vaccine" searches started to pick up in August, gaining steam after the US Food and Drug Administration approved the first Covid-19 vaccine, according to Konkel.

However, she noted the non-mandate postings represent an "incredibly small" percentage of Indeed's US job listings.

As of November 5, fewer than 0.01% of job postings and about 0.01% of US searches contained the phrase "no vaccine required" or some iterations thereof, according to the most recent data from Indeed. Meanwhile, 2.53% of US job postings on Indeed mentioned requiring a vaccination.

On Tuesday, a search conducted by CNN Business for "no vaccine required" listings on Indeed's website returned about 230 results.

However, traditional job sites aren't the only avenue for these types of postings. JP Valadez, of NextGen Code Company in Lubbock, Texas, launched the NoVaxMandate.org online job board in August. Since then, the site has had more than 2.25 million unique visitors and more than 20,000 resumes posted, Valadez said. As of November 12, the site had roughly 500 active listings.

"We are also seeing a massive migration from corporations to smaller businesses," he said in an email to CNN Business. "Many in the health industry are completely abandoning their career path in favor of something completely different. We are seeing nurses and doctors apply at travel agencies, for example, and just the other day we saw a resume from a NASA data analyst who was willing to work as a plumber or an electrician as long as the employer respected their values and their bodily autonomy."

Dozens of the businesses listing "no vaccine required" job ads that were contacted by CNN Business declined interview requests or did not return calls and emails seeking comment. Several, however, did share their perspective.

Philip Dulock, an owner at Spanish Oak Assisted Living in Pflugerville, Texas, said he noticed a sharp uptick in applications after he included the phrase "NO VACCINE REQUIRED" in the title of a job posting for a certified nursing assistant.

It's been a challenging couple of years trying to hire qualified staff, he said. After some of the larger health care organizations in the region started implementing vaccine mandates, Dulock said he figured the phrasing could help get some people through the door.

Considering the majority of the staff and the entirety of the residents are vaccinated, he said he feels like the risks are lower.

"As far as I'm concerned, if someone does not want to get vaccinated, that's their choice," he said. "We're all protected by the vaccine."

In Nampa, Idaho, Allegiant Supported Living, which provides personal care services to adults with developmental challenges, is fully funded by Medicaid, meaning that employees' wages are at the mercy of slow-to-adjust reimbursement rates, owner Jenny Fultz told CNN Business.

Knowing that Allegiant isn't able to easily raise wages, Fultz said she has tried pulling a variety of levers -- such as sign-on bonuses and a raffle for a trip to Las Vegas -- to attract employees at the expense of the company's bottom line. In recent weeks, Fultz added the "no vaccine required" phrase into the online postings for jobs at several locations in the region.

"I don't have the luxury of narrowing the employee funnel," she said. "We are placed in a desperate situation for employees to provide critical services."

Fultz said she's paying close attention to federal guidance and will adjust her company's requirements as needed. Her business is classified as a Medicaid home and community-based service, which is currently exempted from the Centers for Medicare and Medicaid Services' interim final rule issued earlier this month that requires Covid-19 vaccinations for certain health care organizations that receive federal funding.

Generally speaking, mandating vaccines in the workplace is legal as is not requiring vaccines, said Dorit Rubinstein Reiss, professor of law at the University of California Hastings College of Law. However, the latter group runs a higher risk of Covid-19 outbreaks and potential workers' compensation claims if they can show they were infected on the job, she said.

The Biden administration's vaccine rules for private employers were set to go into effect starting January 4; however, a federal appeals court has blocked the mandate.

Separately, several states have sued the administration over the Centers for Medicare and Medicaid Services' rule requiring workers at certain health care organizations to be vaccinated. The lawsuit alleges the requirement is unlawful.

If federal vaccine mandates withstand legal challenges, businesses with more than 100 employees and health care organizations may face hard choices, Reiss said.

"For health care: They may, if the courts do not intervene, have to choose between accepting Medicare/Medicaid and allowing unvaccinated workers," she said, adding that those employers might also try to be overly generous on allowing exemptions to any vaccine mandate that might go into effect.

Vaccine mandates are well within the purview of the government and within the Occupational Safety and Health Administration's responsibility of ensuring employees have a safe and healthy workplace, said Stacey Lee, associate professor of law and ethics at the Johns Hopkins Carey Business School in Baltimore, Maryland.

"I think Covid checks those boxes," she said.

The federal orders out of the Biden administration, OSHA and the Centers for Medicare & Medicaid Services help to "take the burden off the employer for having to be the 'bad guy,'" Lee said.

There are plenty of historical precedents for mandates, Lee said, noting that the polarization and the politicization of the coronavirus has made it difficult for them to be put into place now.

"What has changed is, perhaps, a new interpretation of individual freedom, individual liberty and an increasingly divergent view of what medicine or science requires as a response to the pandemic," she said.