Travel expert Eoghan Corry has suggested airlines 'will take anything' to get back in the air.
He was speaking after Ryanair launched a COVID-19 Travel Wallet, which is available in its app.
It means those who need to travel can upload negative PCR tests, COVID vaccination certs and other documents that may be required for EU travel this summer.
Eoghan told Newstalk Breakfast the system is being used by other international carriers.
"Aviation has been looking for something to get them out of the terrible position that they're in, where international travel has been effectively come to a halt.
"They've been working on a travel pass, a travel passport, which shows you've been vaccinated... it was initially designed when PCR testing was what was being talked about.
"It's been trialed by Emirates and Etihad, that's what IATA [International Air Transport Association] - the big international body - are running with.
"What Ryanair have done is put this facility into their app where you scan....the evidence of your PCR test.
"The facts on the ground are it's havoc out there [with] people being denied boarding on flights."
Asked about a lack of standardised testing system, and whether this is being used to nudge to the EU, Eoghan said the airlines will take anything they can get.
"It's more in hope, aviation will take anything - if they were told to get a stone and run clockwise around the airport they'd say 'Oh lets go with that'.
"What they're listening to is [European Commission President] Ursula von der Leyen, for instance, saying within a month the EU will have some sort of legislation up - that sounds very, very hopeful."
Families and summer travel
Eoghan added that some countries are also moving forward with their own plans.
"Cyprus has decided, from May, they'll let people in who have a vaccination certificate, Greece did the same.
"In Spain, the tourism minister said they're opening in May... and Portugal are also talking.
"But... it's going to take a long time before we get something that's internationally agreed".
On questions of discriminations against those who are not vaccinated, Eoghan said this could be around children and family holidays.
"There's going to be all sorts of issues, especially when children are not vaccinated.
"And if we get back into a situation where leisure travel is open and families can't go, that's when the tourism industries will start to hurt".
The EU is working on a proposal of a vaccine passport for people who have been inoculated against the coronavirus.
It is thought this could see people who have had the jab present a vaccination certificate when travelling across borders.
However Dublin MEP Barry Andrews has said as Ireland is outside the EU Schengen Area, and shares a Common Travel Area with Britain, UK cooperation would be important.