The Taoiseach says health officials are 'hugely concerned' as the so-called 'UK variant' which emerged in December now accounts for 90 per cent of Covid-19 cases.
It comes as the death toll from the virus exceeded 4,000 here yesterday, and more than 6,000 on the island of Ireland.
57 additional deaths were reported last night, along with 650 new cases.
There are 765 patients in public hospitals with the virus, while there's 154 in ICU.
Dr Gerald Barry, an assistant professor of virology in UCD, says the decline in cases may slow down in the coming weeks.
23 of yesterday's 650 Covid-19 cases were in Cavan and Monaghan.
Monaghan remains the county with the highest incidence rate of the virus in the country at 449.6.
There were 14 positive cases there in the past 24 hours.
Cavan had the remaining 9 cases and the incidence rate is just above the national average at 282.2.
