The Department of Health has been notified of 5,325 new Covid-19 cases and 17 further deaths.
Ministers have been told that the new strain of the virus, originally seen in the UK, is now accounting for around 25% of cases according to samples.
To date, there have been a total of 113,322 confirmed Covid-19 cases and 2,282 coronavirus-related deaths in Ireland.
In a statement, the National Public Health Emergency Team said that 16 of today's reported deaths happened this month.
The number of patients being treated in intensive care today is up six to 76.
As of 2pm, there were 840 people hospitalised with Covid-19. NPHET said there have been 102 additional hospitalisations in the last 24 hours.
Of the cases notified today, 2,550 are men and 2,769 are women, with 63% under the age of 45, while the median age is 36.
There were 1,931 new cases in Dublin, 767 in Cork, 323 in Kildare, 322 in Limerick, 238 in Donegal, while the remaining 1,744 cases are spread across all other counties.
The 14-day incidence rate of the disease now stands at 674.4 per 100,000.
The counties with the highest incidence rate are Monaghan (1,243), Louth (1,173.1) and Limerick (1,113.4). The counties with the lowest incidence rate are Wicklow (323), Tipperary (326.5) and Westmeath (376.3).
The Chief Medical Officer said there is now a considerable surge in Covid-19 cases and hospitalisations, which can be turned around if people stick to the measures that worked last spring.
Dr Tony Holohan said: "We have seen some early progress in that the average number of contacts per case has been dropping in recent days, but we need to continue this effort to limit as much as we can our contact with other people in the days and weeks ahead.
"If we all stay home and keep to the public health advice, we can bring Covid-19 back under control, which ultimately will protect our essential services such as Health and Education and most importantly save lives."
The Cabinet sub-committee on Covid-19 is meeting to discuss the spread of the virus, with the closure of schools this month among the proposals being discussed.
The Taoiseach earlier told RTÉ's News at One that the Government was looking at the extension of school closures until the end of the month, and that any decision on schools will be focused on preserving the school year.
Micheál Martin also said that further restrictions and the possible closure of construction and manufacturing services were to be discussed at the meeting, with the committee considering further measures to "reduce mobility".
The number of people with Covid-19 in hospital is close to the peak of the first wave and the Health Service Executive expects this number will be surpassed by the end of the week.
It comes as an agreement between the HSE and private hospital groups to provide extra capacity is expected within days.
Any overall deal is likely to be for a period of about 12 months and would involve individual private hospitals or hospital groups agreeing their own particular terms regarding HSE access to a percentage of their capacity.
The Private Hospitals Association has said that talks with the HSE are at "an advanced stage".
Meanwhile, 335,600 people were due to receive the Pandemic Unemployment Payment today, an increase of almost 58,000 or over 20% since 22 December.
According to latest figures, around 23,000 payments were made between Christmas Eve and 30 December to people who became unemployed in the week before Christmas, as tighter public health restrictions were re-introduced.
This week's payments amount to just over €99m, bringing the total cost of the PUP scheme since its introduction last March to over €5bn.
