Stormont Ministers are to meet next week to consider potential new coronavirus restrictions for Northern Ireland.
Ministers will convene on Wednesday to decide what steps will be required in response to the threat posed by the Omicron variant.
At a meeting at Stormont on Thursday, Executive Ministers received a stark briefing from officials on what the next number of weeks could hold if action is not taken.
A briefing paper warned “significant intervention” could be required immediately after Christmas to keep Covid-19 hospital inpatient numbers below 1,000.
A Department of Health modelling paper said that would be the scenario facing the Executive if Omicron turns out to be “close” to the severity of the Delta variant.
The peak of Covid-19 hospital inpatient numbers during the pandemic in Northern Ireland was 1,055 in January this year.
After Thursday’s Executive meeting, deputy First Minister Michelle O’Neill tweeted: “More data available next week, which will give a clearer picture of impacts & steps we may need to take.
“Evidence shows that getting booster vaccine is vital in our defense – please get yours.”
The Department of Health briefing paper, seen by the PA news agency, outlines how Omicron is expected to spread in the region.
It stressed the severity of the variant remains “uncertain” and it is likely that booster vaccinations offer protection against severe illness.
“It is likely that a peak in case numbers will occur in the middle third of January, with hospital admissions and occupancy peaking in late January/early February,” the paper added.
“The extent of the hospital peak will depend on the severity of Omicron illness, but without further measures is likely to exceed numbers observed earlier in the epidemic, potentially several fold.”
The paper said data from England and Scotland expected in the next week or two will allow the initial modelling estimates for Northern Ireland to be “refined”.
It added: “However, if Omicron is associated with disease severity close to that of Delta, significant intervention would be required immediately after Christmas at the latest to have a reasonable chance of keeping hospital inpatient numbers at less than 1,000.”
Details of the modelling paper emerged after it was confirmed that Northern Ireland’s booster rollout will further accelerate next week when vaccination centers open to the over-18s.
Some GP and community pharmacies are already offering jabs to the 18-29 age cohort.