The two top medical advisers to the Northern Ireland Executive have said they cannot rule out further Covid-19 restrictions before Christmas.
The chief medical officer (CMO) and chief scientific adviser (CSA) said there are so many unknowns about the Omicron variant that it is not possible to predict what measures may be required to keep it under control.
On Wednesday, the First Minister said he does not believe further restrictions will be required before Christmas.
"I don't envisage there being further restrictions before Christmas, the current measures that we have in place, if people follow that, that will be able to get us through the Christmas period," Paul Givan said.
Speaking at a media briefing later in the day, CMO Professor Sir Michael McBride said: “I wish there were elements of certainty about anything we have been faced with over the last 21 months.
“I think one thing we can say is there is a high degree of uncertainty and there has been throughout the pandemic.
“What we can say with a high degree of certainty, this is a much more transmissible virus and that being the case it is likely it will out-compete Delta and therefore will probably, in a short period of time, replace Delta as the dominant variant.”
Professor Ian Young, the chief scientist, said: “I’m a scientist, people are always trying to get me to say things for certain and the nature of science is uncertainty.
“There is always uncertainty, I think it is highly likely Omicron will become the dominant form of the virus given what we understand about it at the moment and we need to observe the trajectory of it in Northern Ireland very closely.
“I think it is unlikely it will be the dominant form of the virus in Northern Ireland before Christmas but that is not a guarantee of what will happen, there can’t be a guarantee.
“All I can promise with 100% certainty is that we will monitor the data and the spread of epidemic very closely and advise accordingly depending on what we observe.”
However, both men urged the public to adhere to the current public health guidance in a bid to reduce the likelihood of further measures becoming necessary.
Prof McBride also said there are currently no plans to review the close contact guidance for schools in Northern Ireland.
However, it was revealed that some people diagnosed with Omicron will be required to isolate for 14 days.
Dr Brid Farrell from the Public Health Agency said this will be assessed by contact tracers on a case-by-case basis and would apply to people who work in healthcare settings.
Prof Young also poured cold water on hopes that Omicron may result in Covid-19 becoming less dangerous, and described early evidence from South Africa that Omicron is leading to people suffering less severe illness as “low confidence at the moment”.
He continued: “There is a lot of discussion about how, in the long term, viruses tend to evolve towards forms which cause less severe disease and there is a little bit of truth to that.
“But it’s a long process and a bumpy road and what we have seen with Omicron is that it can easily evolve into a form of the virus that is more difficult and more severe, as we saw when Alpha was replaced by Delta.
“I would hope it would be good news if Omicron turns out to be less severe but there is absolutely no guarantee at the moment that that is the case and even if Omicron is less severe, I am afraid that there will be new letters and new variants in the months and years to come.
“So we are not at the end of Covid, at some point we will transition through from it being a pandemic to it being endemic, a background disease in our population, but I think there is quite a long way to go before we are there yet.”