According to Nancy Rothbard, professor at the Wharton School, companies should encourage their employees to get vaccinated against Covid through incentives, not mandates.

“There are many challenges to assign employees to do anything,” said Rothbard on Thursday in the “Squawk Box” of CNBC. “Any boss will tell you, it’s a lot more about persuasion than telling a story.”

The question of whether workers need to get vaccines to return to the office has come into focus lately, with around 3 million people shot dead in the US every day. The latest figures from the Centers for Disease Control and Prevention show that nearly a quarter of the adult American population is fully vaccinated.

While many experts believe it is legal for employers to make vaccines mandatory, business leaders may worry about alienating employees.

“Trying to really motivate people to get vaccinated is going to be a much more popular avenue than mandates, in my opinion,” said Rothbard, a management professor whose research has focused in part on work motivation and engagement.

Companies like Tractor Supply offer their employees one-time cash payments to encourage them to get a Covid vaccine. The aim is to offer hourly workers up to four hours of wages – two hours for each dose of Pfizer and Moderna vaccines that require two shots. It also aims to help with paying for Lyft rides to and from appointments.

Johnson & Johnson’s vaccine, the only other emergency approved by the Food and Drug Administration in the United States, is just one dose.

Companies should consider employee preferences regarding vaccination status disclosure, Rothbard said, adding that some people are less comfortable sharing personal information of any kind with employers and colleagues.

“There are ways to do this more privately when you want to take a member of staff aside and say, ‘See, have you been vaccinated? … If you haven’t, we need to take alternative precautions'” for the safety of others, she offered.

The debate over vaccine disclosure in the workplace does not reduce the need for Americans to be vaccinated to end the pandemic, Rothbard said. “The term ‘herd immunity’ implies that it has a collective cost, not just an individual choice that people make when they choose to be vaccinated.”

Despite the importance, Rothbard stressed that incentives are likely to be effective in helping companies achieve high vaccination rates among their employees.

“I have a newspaper called ‘Mandatory Fun’. People don’t even like it when they are forced to have mandatory fun when they don’t feel legitimate in the workplace,” she said. “People don’t respond well to mandates. They respond better to incentives and encouragement.”

Evidence of vaccines for customers

Whether or not customers need to show proof of vaccination in order to receive services in a business – such as eating out in a restaurant – has become another controversial issue in the US. Some critics have raised concerns about civil liberty, while proponents of the so-called vaccination passport say that requiring people to prove they have been vaccinated benefits public health and allows the economy to reopen safely.

Last week, Florida Republican Governor Ron DeSantis signed an executive order preventing companies from requiring a customer to provide evidence that they received a Covid vaccine as a requirement for service. In his order, DeSantis claims that Covid vaccine passports “restrict individual freedom and compromise patient privacy”.

Texas governor Greg Abbot issued a similar order Tuesday banning the state government and private entities receiving public funding for requiring Covid vaccination certificates.

Dr. Scott Gottlieb, a former FDA commissioner, told CNBC on Wednesday that he believed the conversation about reviewing vaccine status was not okay.

“I think we were thinking about vaccination cards through the wrong lens. I think the way they are likely to be used is to create two access routes to different venues,” Gottlieb said in an interview on “Squawk Box” . “”

Covid testing may be required along with secondary symptom screening for people who cannot prove they have been vaccinated, said Gottlieb, who is now on the board of directors at vaccine maker Pfizer.

“The other will be in a fast lane. If you can prove that you’ve been vaccinated, you don’t have to provide evidence that you’ve recently been tested,” or go through some sort of symptom screening, Gottlieb said.

“It will be like an E-ZPass where you can either go through the fast lane or if you still want to pay the toll because you think the police are following you with the E-ZPass device, you can stop and stand in line and pay the toll, “he said.

Disclosure: Scott Gottlieb is a CNBC employee and a member of the boards of directors of Pfizer, genetic testing startup Tempus, health technology company Aetion Inc., and biotech company Illumina. He is also co-chair of Norwegian Cruise Line Holdings and Royal Caribbean’s Healthy Sail Panel. The Associated Press contributed to this report.