Some Krispy Kreme stores nationwide are handing out free doughnuts this spring to people who can prove they're vaccinated against COVID-19.

In Florida, the NBA's Miami Heat has established a vaccinated-only seating section for fans who show documentation that they've gotten two shots of Pfizer or Moderna or a single shot of Johnson & Johnson vaccine.

Farther north, the state of New York is piloting a mobile phone app that works like an airline boarding pass, displaying vaccine status for those attending theaters and sporting events.

As vaccination against COVID-19 ramps up across the U.S., interest is growing in establishing technology to quickly verify a person's immunization status. Proponents say the systems, sometimes referred to as "vaccine passports," could allow economies to gradually reopen before herd immunity is reached by assuring consumers that they are safe to return to stadiums, theaters and other venues.

But critics see ethical dilemmas.

Many Republican lawmakers say it threatens individual freedom and pressures people into getting vaccinated when they might not otherwise do so. The Biden administration is on record saying it won't develop the technology, preferring to leave it to the private sector to sort out and implement. And DFL Gov. Tim Walz last week told reporters he had "no intention of doing vaccine passports."

As the debate over the issue swirls, the technology behind digital vaccine passports is still being developed. Doctors argue that limiting attendance based on vaccine status is premature because many still don't have access to immunizations. It's also not yet clear how long vaccine protection lasts, they point out, or how different vaccines will work against new variants of the virus that are emerging.

"The science isn't there yet to support broad-based implementation, nor is the equity there," said Dr. Peter Bornstein, an infectious disease specialist in St. Paul.

At this point, the most visible proof of vaccination for most Americans comes via a small white card that they receive after vaccination. Health care providers fill out the cards, which list a patient's name and the vaccine received. For now, the cards suffice as documentation for incentives such as the free doughnuts and special seats at Miami Heat games.

Passes in use elsewhere

The Excelsior Pass system in New York, meanwhile, is one of several governmental and private sector examples of digital systems to verify vaccine status, according to an article last week in the Journal of the American Medical Association (JAMA).

In Israel, a smartphone app called a "green pass" allows vaccinated people access to public venues such as gyms, hotels and entertainment venues. The European Union is planning a "Digital Green Certificate" that would allow for unrestricted travel.

Lawrence Gostin, a law professor from Georgetown University who authored the JAMA article with two fellow health-law specialists, wrote that as long as demand for vaccine exceeds the supply, digital health passes (DHPs) would unfairly exclude people who simply cannot find a shot.

"Yet once everyone can gain access to vaccines, there is a strong ethical justification for DHPs designed to create safer environments to work, shop, recreate, and travel, as they represent a less restrictive alternative to current public health measures," they wrote. "Unvaccinated individuals have no right to impose risks on others, thus impeding a return to normal activities."

Still, there are challenges.

People who can't be vaccinated for medical reasons should not be excluded from privileges, Gostin and colleagues wrote, and exemptions might be needed for religious or conscientious objections. They noted, too, the "historic distrust of the health system" among racial minorities and said that distrust, and a reluctance to get vaccinated, "should not disqualify them from economic and social opportunities."

Vaccine passports should not be mistaken for vaccination mandates, Mark Hall, a health-law expert at Wake Forest University, wrote in the New England Journal of Medicine. Passport systems would not restrict access to workplaces, schools and health care institutions but could help create standards for reliable documentation of vaccine status that are then used in the travel industry and elsewhere.

"Allowing sports leagues, concert and sporting venues, clubs, restaurants, and bars some latitude to set rules that determine access on the basis of customers' vaccination status would be reasonable; doing so may also serve wider efforts to encourage vaccine uptake," Hall and a colleague wrote last month in the journal. "Although not in the driver's seat, government will have to help steer."

Politics heat up debate

In recent weeks, the issue has emerged as a political flash point.

Republican governors in Florida and Texas have taken steps to block passport programs. After Walz told reporters last week he wasn't interested in vaccine passports, Sen. Michelle Benson, R-Ham Lake, posted an online video saying Senate Republicans would make sure he kept his word.

"It sounds real Orwellian to me," Paul Gazelka, R-East Gull Lake and the Senate majority leader, said in an online video also posted last week.

Last month, the Minnesota-based Citizens' Council for Health Freedom called vaccination passports a "stealth move to tyranny." The group called the idea "coercion at its finest."

Andy Slavitt, senior adviser to the White House's COVID-19 response, said during a press briefing last month that the Biden administration is not creating a vaccine passport system and would only help developing criteria for systems. The subject is "tricky and important," Slavitt said, since people will want to show they've been vaccinated.

"We view this as something that the private sector is doing and will do," he said.

Right now, the utility of vaccine status for granting admission to the theater, sporting events and other venues is limited, Bornstein said, because the science behind the vaccines and the virus is still in flux.

Vaccines are being provided under an emergency use authorization and haven't yet been fully approved by the Food and Drug Administration. While Bornstein said he had no reason to be hesitant about the vaccines, he believes some people are waiting for more information or full FDA approval.

"It's premature," he said of vaccine passports. "Ask me again in two months — if we have ample supply of vaccine and a better understanding of how well vaccines work against emerging variants, then I might have a different answer."

Developers of vaccine passport systems must ensure that data can be kept secure and private, said Joel Wu of the Center for Bioethics at the University of Minnesota. Those concerns are growing as more breaches occur in private-sector enterprises.

More broadly, it's not surprising that vaccine passports would prompt debate, Wu added, since they involve trade-offs between individual freedoms and collective safety — familiar issues in debate over topics from speed limits to smoking.

"What are the burdens or inconveniences or limitations that we are willing to tolerate," he asked, "to be able to maintain the conditions for everyone, including us, to be healthy, safe and free?"

Staff writer Jeremy Olson contributed to this report.

Christopher Snowbeck • 612-673-4744