• Experts say it's unlikely an international COVID-19 passport travel system will come about.
• They have flagged privacy, inequality, politics, and long-term need as the main problems.
• Still, the travel industry is banking on a system to allow international travel to resume.
• See more stories on Insider's business page.

COVID-19 passports have been hailed as the key to opening up the global economy, but some privacy and health experts doubt they'll ever be widely accepted.

Plans to require COVID-19 passports for international travel or even entry to large venues or work offices may fumble, as critics say there's a wide range of issues – from privacy and inequity, to continuity and longevity – standing in the way. But airlines, which took a trillion-dollar hit because of the pandemic, are banking on some kind of digital credential to get people flying internationally again.

The most likely outcome, said Bryan Del Monte, president of the Aviation Agency and a former director at the US Department of Defense, is that health passports will likely be needed only if you plan to travel internationally, but they won't be "as big a deal as everyone thinks."

But by the time a system is agreed upon and created, this could be a "moot" point, he told Insider.

"The vaccine passport could wind up being irrelevant because by the time everyone gets inoculated, do you really need one?" he said, noting that travelers don't provide proof of vaccination against measles or rubella upon entering a foreign country.

Even so, these health passports have begun rolling out as proposals or beta tests, and some have even gone live in various markets across the globe.

The European Union proposed the "Digital Green Certificate," a vaccine passport which would allow travel to 27 member countries, if approved. China, Israel, the UAE, and the Philippines are among other countries that have launched versions of their own, as well.

In the US, the White House is reportedly working on a vaccination passport that could require proof of immunization prior to traveling or entering crowded venues. And New York was the first state to launch one that would show a person's proof of vaccination before entering large gatherings, like a basketball game or a wedding.

Nobody is talking about the 'politics that go into this'

The World Health Organization, and even airlines, have advocated against requiring vaccination for travel. The main reasons are data on how effective vaccines are at preventing transmission plus the limited global supply, according to the WHO.

"If access to vaccine is (unequal), then inequity and unfairness can be further branded into the system," Mike Ryan, the WHO's Health Emergencies Programme executive director, said on March 8.

In February, the WHO said wealthy countries with just 16% of the world's population bought up 60% of the available COVID-19 vaccine supply. It flagged the inequality in the global immunization effort, but also said the imbalance could cause the virus to continue spreading and mutating to more dangerous variants.

In the US alone, the vaccine rollout has been disproportionate among minorities and poorer populations, who have received fewer doses of the COVID-19 vaccine despite often being at greater risk for contracting the disease.

Read more: COVID-19 Vaccine Tracker: AstraZeneca's shot proves safe and effective, and is headed to the FDA

Some have also said international COVID-19 passports becoming standardized and globally adopted could be too big a task to accomplish.

"The technology to make this happen is very difficult, but the even more difficult part that no one's talking about is the politics that go into this," said Bryce Conway, consumer advocate and founder at 10xTravel, a company that helps more than 70,000 travelers navigate loyalty programs and credit card points.

In the US, for example, some Republican lawmakers have dubbed the concept of vaccine passports as dystopian.

"We can't even agree how to row the boat in this country," Del Monte said. "This is not going to roll out quickly."

Internationally, if countries approve certain vaccines and not others, some immunized travelers may still be barred from entering. China, for example, has said travelers receiving its vaccine will have an easier time entering the country, and many countries have said Russia's shot isn't effective enough to qualify.

Conway said the most likely scenario, if a COVID-19 passport is adopted, is that various groups of countries will agree on how to accept travelers from one another.

"I don't think you're going to have a multinational, huge system where everyone's on it and that's the one standard that's used," he said

But Laura Hoffner, chief of staff at risk consulting firm Concentric, said the secret to creating a COVID-19 passport is getting the US to lay out protocols. Because once that happens, "the world will most likely follow suit," she said.

On March 12, Jeff Zients, the White House Coronavirus Response Coordinator, said the private sector and others have already begun working on how to prove vaccination.

"Our role is to help ensure that any solutions in this area should be simple, free, open source, accessible to people both digitally and on paper, and designed from the start to protect people's privacy," he said.

Still, the airline industry has asked the White House for specific guidelines on a health passport, so people can get back to flying, as international travel has plummeted 85% because of the pandemic, according to Perry Flint, head of the International Air Transport Association's US corporate communications.

"We're ready to get going again," Flint said.

In a statement to Business Insider, the White House said it is "leading an interagency effort regarding vaccine verification," but didn't give any details on a timeline or how a passport would work.

'We can do all of this with little pieces of paper'

Airline trade groups such as IATA and Airlines for America are advocating for a digital passport that either verifies someone's immunization to COVID-19 or a negative test result, as they say outright mandating the vaccine could discriminate against those who can't or refuse to get the vaccine.

While waiting for guidance from the government, IATA has begun testing its own digital passport, called the Travel Pass. Doctors can send test results or proof of vaccination to a person, who can link that information to the Travel Pass app prior to flying. Then travelers show the app to an agent, along with their actual passport and ticket.

These digital passports come with another hurdle, though: maintaining privacy.

Immunity passport apps are fraught with privacy flaws and pose big ethical problems, according to a report from security research company Top10VPN, which analyzed 65 digital health certificate apps operating around the world and found 82% had inadequate privacy policies.

Jon Callas at the Electronic Frontier Foundation said the high-tech solution comes with too high a price tag and too high a risk for invasion of privacy. "We can do all of this with little pieces of paper," he said.

Checking thousands of vaccination papers or test results would be a bottleneck to international travel, Flint said, saying the world shouldn't use a "20th Century standard" when many things, such as tickets, have already gone digital.

For years, some countries have already taken on the task of checking proof-of-vaccination papers against yellow fever. This has become known as the "yellow paper," and could be as easily applied to COVID-19, said Callas.

But the yellow card is "not safe; it's not easy," Caryn Seidman-Becker, chief executive officer of CLEAR, said at the Economic Club of New York on March 30. CLEAR, a biometric identity platform used at airports, has created its own "digital health credential," called Health Pass that Seidman-Becker said will make travel "frictionless."

But with regard to digital credentials, Callas said, "I don't see why a paper form isn't good enough. Every immigration form that I do, I sign it at the bottom, and say under penalty of perjury I assert this is true, and I don't see why, 'I got my COVID-19 vaccine' isn't just another box to tick."

"They're trying to sell digital passports," he said "The people who are advocating this are the ones who want the rest of us to pay for that."