A system of vaccine passports could ultimately allow the return of international travel, MSPs have been told, while some countries are already requiring vaccination "green passes" for entertainment venues.
Professor Devi Sridhar of Edinburgh University spoke to the Scottish Parliament's Health Committee about international travel regulations during the pandemic.
The Scottish Government adviser said that if coronavirus vaccines significantly reduced transmission of the disease, as initial evidence suggested, electronic vaccine passports could help to restart international tourism.
She said EU countries were already developing plans for a digital green pass, with countries like Spain and Greece keen to welcome visitors again.
Prof Sridhar said: "I think if these vaccines stop transmission, which they look like they might, we will reach a stage of vaccine passports.
"It's already being discussed in the EU. We already have countries like Israel introducing green cards domestically, if you actually have gotten vaccinated.
"I think similar to yellow fever, where the WHO has certification if you've been vaccinated, we will reach a state where aviation will continue.
"Spain and Greece are really keen on this for their tourism industries.
"You will be allowed to fly and we can have international mobility, but only when people are vaccinated and we have that confirmation that you will not infect others when you travel."
She said airlines have also collaborated to create an application called CommonPass, which allows passengers to upload medical information such as test results or vaccination status, and generates a pass in the form of a QR code.
Prof Sridhar said this could lead to a two-tiered approach as many poorer countries in the world do not yet have access to vaccines.
Some countries were considering using vaccination certificates domestically to allow people to access clubs or bars, she said.
Prof Sridhar said: "Israel's introduced this green pass system.
"This is also to encourage young people to get vaccinated because many people in their 30s think: 'Why should I get vaccinated?"'
Younger people play an important role in spreading the disease, she said, adding: "We know it's (people aged) 20 to 40 who spread it, people who suffer are over 60 and then those who have health issues.
"That's kind of the problem of Covid - who it affects isn't who spreads it.
"And then you can really start creating an incentive for people to say: 'If you want to go to the concert, if you want to be able to be active in places where spreading occurs, then you have to protect and make sure you're not infecting others."'
She said Scotland should be considering how any vaccine passport system would be handled properly.
