Professor Luke O'Neill says 'it seems unlikely' the new variant of coronavirus hasn't reached Ireland.
However, the leading immunologist said scientists are "99% sure" coronavirus vaccines will be effective against the new strain that's been reported in Britain.
The British government has warned the new strain could be 70% more transmissible.
They've suggested it's responsible for a rapid spread of coronavirus across much of south England recently.
It has prompted many European countries - including Ireland - to introduce temporary travel bans to stop passengers arriving from Britain.
A number of recent confirmed cases of COVID-19 are being examined for any evidence of the new strain.
Professor O'Neill said the variant had been spotted earlier in the year, but now evidence seems to suggest it does indeed increase transmission of the virus.
He explained: "That's mainly based on correlation at the moment - they've noticed this variant going up and up and up in London, say, and it correlates then with increased spread.
"There is evidence that the bits that have changed may make it stick more to your lung cells... it seems to make the spike protein more sticky."
He said human behaviour - such as people not following guidelines - could be a factor in the spread of the virus, but there is some biochemical evidence behind the current concern in the UK.
He explained: "It did go from 28% in London in November to 62%... that's a rapid growth. Can that just be explained by human behaviour? It seems unlikely... it probably is more transmissible.
"It's in Italy, it's in Wales, it's in Scotland, more and more reports are coming out it's in other place as well... it seems unlikely it wouldn't have come here, especially if it's transmissible.
"In Ireland they will be looking for it. I bet you in the next one or two or three days, there may well be a report of a case in Ireland."
Professor O'Neill said scientists are extremely confident the COVID-19 vaccines will be effective against this new strain.
He said: "The great thing about the Pfizer and Moderna vaccines is you can modify them very quickly if the strain did become resistant.
"If, and it's extremely unlikely, another strain emerges that has lots of changes... you can change the vaccine very, very quickly. That's one thing we don't need to worry about when it comes to these strains."
European regulators are meeting today to discuss whether to approve the vaccine for use in the EU.
Professor O'Neill says three vaccines could be approved for use here - from Pfizer / BioNTech, Modern and AstraZeneca / Oxford - very shortly.
He said European officials are being "very careful and rigorous" before making their decision.
However, he suggested "there's no way they can't approve these vaccines now" as more and more other countries give them the green light.