The World Health Organisation (WHO) has flagged the use of “e-vaccination certificates” as having the potential to unlock international air travel as nations prepare to rollout mass vaccination programs.

Medical expert Dr Siddharta Sankar Datta told a virtual briefing in Copenhagen on Thursday that the agency is investigating using technology to prove travellers are fit to fly.

“We are looking very closely into the use of technology in this COVID-19 response, one of them how we can work with member states toward an e-vaccination certificate,” he said.

The agency does not support using “immunity passports” as some countries have suggested as a way of getting travel and large-scale events back on track.

But it has signed an agreement with Estonia to work on “digital innovations in the COVID-19 response,” which involves using certificates for those who have had a vaccine.

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The UK became the first country in the world to approve a vaccine for use this week with the Pfizer/BioNTech version to be rolled out within days for those most in need.

The move has seen medical authorities at pains to point out no “corners had been cut” in the approval process. Older people, healthcare workers and those who are clinically vulnerable will be among the first to get it.

Last month Qantas CEO Alan Joyce suggested that those who wanted to take a seat on the flying Kangaroo would need to be vaccinated first.

“I think that’s going to be a common thing talking to my colleagues in other airlines around the globe,’’ he said, sparking questions about legality.

Medical experts in the UK will not make the vaccine mandatory.

Prime Minister Scott Morrison has previously suggested vaccination will be “as mandatory as you can possibly make it” in Australia before walking the comments back.

“There are always exemptions for any vaccine on medical grounds, but that should be the only basis,” he said in August.

Despite the desperation of many to put travel back on the agenda, a report out Thursday from the UK University of Exeter found that digital health passports should not be introduced until vaccines and tests are ready and affordable for all.

The authors feared failing to address issues around access to testing and vaccines could restrict people’s legal rights and lead to privacy issues.

University of Exeter Law School’s Dr Ana Beduschi said: “Digital health passports may contribute to the long-term management of the COVID-19 pandemic, but their introduction poses essential questions for the protection of data privacy and human rights.

“They build on sensitive personal health information to create a new distinction between individuals based on their health status, which can then be used to determine the degree of freedoms and rights individuals may enjoy.”

“Given that digital health passports contain sensitive personal information, domestic laws and policies should carefully consider the conditions of collection, storage and uses of the data by private sector providers.”

“It is also crucial that the communities that have already been badly impacted by the pandemic have swift access to affordable tests and, eventually, vaccines. Otherwise, deploying digital health passports could further deepen the existing inequalities in society.”