Talks among EU member states are ongoing and international airline Qantas has said it will require passengers to have certificates.
Mr Donnelly said he expects the use of vaccine certificates to “evolve” as more is known about the impact of vaccines in the coming months.
“If it were the case that there was a huge impact on trying to massively reduce transmissibility, then we can think about choosing vaccine certs in a particular way,” he said.
“If it turns out that actually it’s a marginal impact on transmissibility then we might have to think about it differently.”
Mr Donnelly also revealed the vaccination programme may begin before the end of the year if the European Medicines Agency clears the Pfizer vaccine by December 21.
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The head of the Covid-19 vaccine task force Professor Brian MacCraith has said that Ireland may receive enough of the Pfizer-BioNTech vaccine in the first delivery to inoculate 2,500 people.
He was speaking at the Oireachtas Health Committee, which also heard that although the rollout of the vaccine has been rapid it has not been rushed or reckless.
Professor McCraith said the successful rollout of the vaccine is dependent on co-ordination across Government, several state agencies and the Health Service Executive.
It outlines the logistics and planning that will be required for large groups to be inoculated against Covid-19.
Sinn Féin s Health spokesperson David Cullinane asked how many vaccines Ireland will get in the first phase of delivery.
Too early to say if new Covid-19 strain has hit Ireland
Deputy chief medical officer Dr Ronan Glynn said Irish public health experts had received formal notification of a new strain of the virus on Monday through its official early warning system with European colleagues and the UK.
Michelle Devane
It is too early to tell whether a new variant of Covid-19 identified in the UK has reached Ireland, an Irish public health expert has said.
Deputy chief medical officer Dr Ronan Glynn said Irish public health experts had received formal notification of a new strain of the virus on Monday through its official early warning system with European colleagues and the UK.