(CNN) — The door to summer is slowly creaking open in Europe, and for those who want to stroll through it to take a vacation amid ongoing Covid restrictions, the key may soon be at hand.
While borders are likely to remain closed in coming weeks, the European Union is proposing to roll out a Digital Green Certificate, or vaccine passport that will allow those with the required armfuls of approved anti-Covid pharmaceuticals or antibodies from having had the virus, to travel freely. Negative tests could also be used to qualify.
It's a measure eagerly anticipated by Europe's prime tourism destinations, among them Portugal, Spain and Greece, where an absence of visitors over the past year has left gaping holes in national bank balances.
But will it be fair?
While the beleaguered tourism industry has delighted at the plan, which the EU is expected to vote on later in March, there are fears that patchy vaccination rollouts and supplies across Europe could mean some countries will enjoy more freedoms than others.
Likewise, with certain demographics targeted for early vaccination over others, some may be forced to remain at home, watching with jealousy as older citizens, many of whom will have received both jabs before the end of spring, jet off for their time in the sun.
And while the EU's executive body, the European Commission, envisages its new Green Certificate simply as a document for allowing its citizens smooth transit across European frontiers, concerns have been raised that they will also become required for entry into restaurants, bars or other venues and events.
While the newly Brexited UK won't be part of the program, the success of its vaccination program could see special travel deals struck with some EU countries that will allow Brits to bypass the need for certification.
Those EU citizens yet to qualify for vaccination -- or unable to qualify -- could be sidelined from the return to the normality most of us are eager to embrace unless they submit to frequent testing regimens.
A harbinger of this can already be seen at sea. Some major cruise companies are advertising summer departures that will only be open to passengers able to prove they've had a full complement of vaccines.
Anger, say some commentators, is inevitable.
"Only the over 50s will be vaccinated by this summer, so there may well be protests from younger people," Kaye McIntosh, former editor of consumer magazine Health Which? and WI Life, tells CNN Travel. "It adds to the sense of generational unfairness created by austerity, house prices and student loans. I wouldn't blame Gen Z for being angry."
Norbert Hidi, a 24-year-old student from the Hungarian capital Budapest, is among those who expect to be going nowhere.
"To put it bluntly, it's not fair," Hidi tells CNN Travel. "Most of us won't have been inoculated by the summer so that means we can't travel or possibly go to bars or restaurants. The older generation have had the vaccines first because they are most at risk, but it shouldn't mean they have more rights because of it."
Brian Young, managing director at UK-headquartered G Adventures, a travel company that offers a range of options including tours for 18-to-thirtysomethings, is confident vaccine passports will help revive tourism worldwide, even if some will miss out this year.
"With international travel having been almost completely grounded for a year now, it's essential that governments work together to find a uniformed solution to opening borders and allowing holidaymakers to start flying again," Young tells CNN Travel.
"The announcement of the vaccine has seen a surge in confidence in the over 50s and, while vaccine passport proposals would pose a good solution as proof for those who have received the vaccine, it leaves a large portion of travelers, who have not taken or are yet to receive the vaccine, uncovered."
Denmark will become the first nation in the world to roll out a "coronavirus passport" for foreign travel later this month. The idea of immunity passports has been debated amongst European countries since the start of the pandemic. But critics warn such passports could be discriminatory and could affect people's right to keep their medical data private. CNN's Nina Dos Santos reports.
Young says the EU decision to allow unvaccinated individuals to qualify for health passports with a negative test for antigens will help, but could still be a barrier for some to travel.
"The roll out of cheaper testing options is also essential if the cost is to sit with the consumer," he says. "The current cost of PCR tests will deter some travelers, especially if they are required to take multiple tests when traveling."
If approved as planned, the EU's Digital Green Certificate will be valid across all EU Member States as well as Iceland, Liechtenstein, Norway and Switzerland. It will use a QR code with a digital signature to protect against falsification. It'll be issued by hospitals, test centers or health authorities, but the data should be verifiable across the EU via a digital gateway.
The EU says certificates will be issued for approved vaccines. People inoculated prior to the certificate's availability, or outside the EU, should still qualify. It's hoped the certificates will also be valid in countries outside the EU.
It does seem like a golden ticket, but in reality, many European nations may be some way off issuing them at scale. Covid rates are entering their third wave across the continent, prompting new lockdowns in countries such as France and Italy. Ongoing disputes over vaccine supplies and suspicions over the safety of the AstraZeneca jab -- which regulators say are unfounded -- have hampered inoculation rates that were already well below those achieved by vanguard vaccinators such as the UK and Israel.
In Hungary, where the vaccination rate is higher than the EU average, officials feel that the Commission's time would be better spent on the procurement of vaccines for the entire bloc.
"We regard the debate related to the certificate as a fake debate because from Brussels no one is expecting certificates; from Brussels we are expecting vaccines," Gergely Gulyás, the minister heading the prime minister of Hungary's office, said on Thursday. "It would be desirable if Brussels shifted the focus of its activity onto this area."
The certificate plan will need the support of all 27 member states if it is to be passed next week and introduced in June. Amid concerns from countries such as Belgium and Germany that it could result in discrimination, EU leaders have sought to bolster confidence.
"We are proposing a common EU approach that will lead us on the way to our goal of re-opening the EU in a safe, sustainable and predictable way," Stella Kyriakides, commissioner for health and food safety, said this week.
"The situation with the virus in Europe is still very challenging and confidence in decisions taken are crucial. It is only through a joint approach that we can return safely to full free movement in the EU, based on transparent measures and full mutual confidence."
The World Health Organization, which has also expressed grave concerns about the risk of vaccination passports creating a two-tier society, this week proposed its own "smart digital certificate," which it was at pains to insist was not a license to travel.
"This is something different than a passport," WHO Europe Director Hans Kluge said on Thursday. "We do not encourage at this stage that getting a vaccination is the determining whether you can travel internationally or not. It should not be a requirement."
He said there were ethical, practical and scientific reasons for this.
"There is a global shortage of vaccines," he said. "So, this would increase the inequities, and if there's one thing that we learned from the Covid-19 pandemic, it is that the vulnerable people got hit disproportionally."
He said lack of clarity over how long immunity lasts meant that vaccination certification was no guarantee of fitness for travel, likewise uncertainties over whether the inoculated can transmit the virus.
Such concerns haven't stopped some countries from forging ahead with their own certification and passport schemes.
Winners and losers
Israel's "green pass" digital vaccination certificate is being used to allow venues and events to reopen.
ACK GUEZ/AFP via Getty Images
Israel, which has one of the world's highest vaccination rates, is already using a "green pass" to open up restaurants, bars, venues and events. Denmark has proposed something similar with tourism officials recently saying it's essential to ensure a "summer of joy."
Meanwhile some airlines are adopting certification to ensure passengers are virus-free. Australian carrier Qantas has started trial of the CommonPass system which will be necessary for overseas travel when Australia's border reopens.
Other airlines are signing up to a digital pass created by the International Air Transport Association, IATA, which will allow passengers to upload negative Covid test certification to allow smoother passage through airports.
Amid this confusing maze of digital paperwork, it is possible that the might of the European Union may help impose some uniformity and clarity on how global borders can be opened up in the near future.
But as health expert McIntosh adds, there will likely be winners and losers, and there are no guarantees, especially not in the long run.
"The right not to be exposed to a deadly disease outweighs the rights of the unvaccinated," she says. "Maybe that will change if vaccination eventually means Covid-19 becomes something more ordinary, such as seasonal flu -- although that still kills thousands of people every year.
"But no vaccine is 100% effective, so even people who have had the jab are still at risk."