Fears a vaccine passport would create unfair advantages for the healthy and wealthy.
Emirates is hosting a 'vaccinated only' flight this weekend, where all staff and passengers must be fully inoculated.
The three hour joy ride starts and ends in Dubai, with economy seats starting from 400 dollars.
Auckland university medical ethicist Tim Dare told Kate Hawkesby coordinating this between countries is premature, while there are still so many variables.
He says the worry is for people who can't get the vaccine for health reasons, or because they aren't available.
"Placing conditions on passengers is a decision for states to make.
"Airlines can't do it on their own, and vaccine passports won't count for anything unless other countries agree to them."