Health experts believe the newest Covid variant is already circulating in Ireland, despite only one confirmed case of the latest variant being recorded here.
The new mutation, known as Omicron XE, is even more contagious than the other versions of Omicron, and while it is not as deadly as previous forms of Covid, it does still kill.
It is beginning to appear more frequently in Britain, with 1,200 cases confirmed to date and five of these in Northern Ireland as of Monday afternoon.
READ MORE: Key symptoms to watch for as new Covid variant 'Omicron XE' arrives in Ireland
Previous waves of Covid have seen a variant first confirmed in the UK before presenting here in greater numbers.
But the real fear is that the massive surge in India, which has six million cases so far this month, could see a new Covid wave emerge across the world - just when people were beginning to think we were on top of Covid.
Professor of Immunology at Trinity College Dublin, Kingston Mills, is concerned about how much more transmissible the new Omicron XE variant is.
He said: “XE is what's called a recombinant virus between BA.1 and BA.2, so we had Omicron and that was a new variant that emerged in December.
"Then there was a sub-variant of that called BA.2 which is now known as the dominant variant in Ireland and a lot of European countries.
"When a person gets infected with two different viruses, those viruses can recombine to give a kind of hybrid virus, which is a mixture of the genome of one and the other.
"So what you have with Omicron XE is that bits of the BA.1 virus and a bit of the BA.2 to make up the XE, and the spike protein is from the BA.2 version and some of the internal proteins are from BA.1.
"There is a suggestion from data in the UK, in the UK they've had over 1,000 cases of this XE variant, and there's a suggestion that it may be more transmissible than BA.2 by about 10 or 20%."
The Trinity Professor told RTE's Morning Ireland on Monday that there is still a "significant number" of Covid cases in Ireland every day, and while the Omicron XE variant is "reasonably mild in healthy people" he said "two big worries" remain.
"One is that when the vulnerable and the older people get infected, it can still be a very severe disease, especially if they haven't been vaccinated. The second worry is the other variants arising, such as this XE.
"It might not be any worse than BA.2 or Omicron but in India right now, there are a series of new variants emerging.
"In India, the Covid pandemic is out of control again and there were six million cases in April already and there's a concern that there are a lot of new variants emerging.
"I think we'll have to watch that carefully and not get complacent about the fact that this thing is completely over.
"I'm not trying to be scaremongering but I'm just saying we need to be prepared if we do see a variant that completely evades immunity with the vaccine.”
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