There have been 764 new cases of COVID-19 confirmed in the Republic, according to the Department of Health.
Four further deaths associated with the virus have also been reported in the past 24 hours.
The latest figures bring the total amount of cases here to 79,542, while the number of coronavirus-related deaths stands at 2,158.
The numbers are reflective of the denotification of two confirmed cases of the virus.
Of the latest cases, 67% are under 45 years of age, while the median age is 34 years old.
Regarding the nationwide distribution of cases, 284 are in Dublin, 70 in Limerick, 52 in Donegal, 44 in Cork, 37 in Wexford and the remaining 277 cases are spread across another 20 counties.
403 are men and 355 are women.
As of 2pm today, 233 people are now receiving treatment in hospital for the virus after 15 new admissions in the past 24 hours.
Of those patients, 29 are in ICU, up from 28 yesterday.
The 14-day incidence rate per 100,000 of the population now stands at 112.2.
Dr Tony Holohan, Chief Medical Officer at the Department of Health said: "Every indicator of disease severity is moving in the wrong direction, more rapidly than we had anticipated.
"We have particularly strong concerns about the prospect of inter-generational mixing around the festive season.
"On December 11th, the 7-day incidence rate for people aged 19 to 44 was 106 per 100,000 population, by yesterday this rate had more than doubled to 217 per 100,000.
"If these younger people come into contact with their loved ones over the age of 65, we could see a spike in infections in this more vulnerable group."
Dr Holohan warned that this would lead to a "very serious pattern of disease, hospitalisations, ICU admissions and unnecessary deaths”.
He added that if people have been socialising in the past few weeks or over this weekend, then they should consider their Christmas plans "carefully".
He said: "Is it responsible to meet with your family over 65 later this week, if you have not kept your contacts low? Should you cancel your plans?
"We have the very real prospect of COVID-19 vaccines on the horizon. Ensure that your loved ones stay alive to receive them, by keeping your distance from them if you have not restricted your movements to this point.
"As difficult as it may seem, staying away from older family this Christmas will protect them - and it would be an exceptional sacrifice made for the common good.”
'Stay home'
Earlier, Dr Holohan advised people to "stay home", while a senior member of NPHET says it is "only a matter of time" before a new coronavirus strain discovered in England arrives here.
Meanwhile, 505 new cases of COVID-19 have been recorded in Northern Ireland in the last 24 hours.
There have also been 13 additional deaths reported by the Department of Health there.
The Northern Ireland Executive is to meet at 9pm tonight, with the region due to go into lockdown on Stephen's Day.
