"It could first be applied to certain countries and regions with high vaccination rates and that already have policies regarding vaccine passports," said Nguyen Viet Nhung, director of the National Lung Hospital.

Recent research revealed those who have received two Covid-19 vaccine shots have a minimal chance of becoming an infection source, said Nhung. As such, vaccinated people could be considered "safe" from a scientific standpoint, meaning Vietnam could now design a framework to approve "vaccine passports."

However, as no Covid-19 vaccine enjoys 100 percent efficacy, mostly ranging from 60 to 90 percent, new variants could be resistant to current inoculations and pose "a small risk," he said.

Nhung proposed a vaccine passport framework drawn up by Vietnam should include mandatory Covid-19 testing for entrants, meaning they need to satisfy two requirements before entering the country: a vaccine certificate to prove they have received enough Covid-19 vaccine shots, and a negative test result for the coronavirus before and after entering the country.

Those who satisfy both requirements would not have to undergo mandatory 14-day quarantine, he suggested.

Tran Dac Phu, former head of the General Department of Preventive Medicine, said since countries around the world are preparing for their own vaccine passport frameworks, Vietnam should follow suit.

In the mean time, Vietnam should build databases and the necessary infrastructure to keep track of and hand out vaccination certificates. Such a system would allow authorities to check an individual’s medical and vaccination history. The government should also request relevant authorities to take note of existing vaccination certificates to sync domestic certification with the rest of the world.

The simplest method would be to use QR codes, said Phu.

"Handing out vaccine passports or vaccination certificates to those who had already received enough Covid-19 vaccine shots is a necessary step for Vietnamese citizens to either travel abroad or domestically with convenience and safety," he added.

The steps Vietnam would need to take before such a framework could be realized would involve evaluating vaccine efficacy, figuring out how much time it would take for antibodies to be produced after inoculation, among other questions.

"For now, variants have yet to cause vaccines to lose their efficacy. But when one does and renders vaccines ineffective, we would need to pay attention," he said, adding authorities also need to devise methods to prevent vaccine passport forgery.

Efficacy concerns

Nguyen Huy Nga, another former head of the General Department of Preventive Medicine, expressed concerns regarding research stating several Covid-19 vaccines are not 100 percent effective.

"The efficacy of a vaccine announced in initial reports is only theoretical. In reality, it might be lower depending on the injection method. As such, though the chance of vaccinated people becoming infection sources might be low, it’s still there," he said.

Nga said Vietnam should wait until more research shows up before it could apply a vaccine passport framework.

Last week, the National Steering Committee for Covid-19 Prevention and Control requested the Ministry of Health to prepare initial steps for a vaccine passport initiative.

The health ministry, along with the Ministry of Information and Communications and major telecom network providers, would flesh out technical solutions for such a framework as soon as possible, ideally by the beginning of April. Such a framework would need to be based on evaluations of the safety and effectiveness of different vaccines and in different countries, the Steering Committee stressed.

As the world started rolling out Covid-19 vaccinations, inoculation certificates have emerged to identify those that have been vaccinated for cross-border travel. China and Israel were among the first to issue digital health certificates for travelers who had been vaccinated against Covid-19, also dubbed "vaccine passports."

The U.S. and Britain are among countries currently considering issuing similar permits, while the E.U. is also working on its own vaccine "green pass", allowing those who have had the jab to travel more freely within the region this summer.

For now, those entering Vietnam, even with a vaccination certificate, would still need to undergo 14-day quarantine.