Great links GeorgC1. I was aware of the Seychelles but not the momentum for vaccine passports in Europe. Here's an article from the Economist that discusses "The Promise and Perils of Vaccine Passports." Its a subscription article but you may be able to get free access so give it a try.

While governments may have difficulty implementing vaccine passport requirements to enter or travel within a country due to legal challenges to such requirements, private companies can implement them fairly easily. Airlines and cruise lines are looking at proof of vaccination as a pre-boarding requirement. We're already seeing widespread government requirements for negative COVID testing to enter.

Vaccine passports are coming and it appears that travelers will welcome them - a survey in the UK produced a 66% acceptance rate for requirements for vaccine passports. Governments can and generally will implement entry requirements for public health purposes that involve some kind of assurance that you are not carrying the virus. These will become more and more common as travel and leisure is a huge part of most county's economies.

https://www.economist.com/science-a...-promise-and-perils-of-vaccine-passports