"Our full expectation is that we're going to see a significant increase in transmission here."
Ireland is at the beginning of a fourth wave of Covid-19, NPHET has warned.
The comments come following 448 new cases of Covid-19 being reported in the country on Thursday, as the
death toll from the virus reached 5,000.
Chair of the NPHET Irish Epidemiological Modelling Advisory Group Professor Philip Nolan said in a statement accompanying the figures: "We have seen an increase in incidence over the last ten days, raising the concern that we are in the early phase of an increase driven by the Delta variant.
"Incidence is growing at 2% per day, reproduction number is now above 1; estimated at 1.0 to 1.2."
Asked during this evening's Department of Health briefing if Ireland was at the beginning of a fourth wave, Chief Medical Officer (CMO) Dr Tony Holohan said: "We think that we see some change now beginning to happen in terms of the incidence.
"We see the five-day average more or less tracking up for about the last week or ten days.
"We see challenges... in some parts of the country, particularly Dublin, and we think that's going to lead us into a further wave of transmission.
"So yes, our full expectation is that we're going to see a significant increase in transmission here."
The CMO said this was the experience that's been seen across many parts of the UK, particularly Scotland.
On Scotland, Holohan stated: "They've seen their case numbers go from something in the order of about 200 a day - which is less than us - about six, seven weeks ago to the reported 4,200 yesterday.
"There's every reason to believe, and that's our belief, that we're facing a significant wave of Delta-driven transmission.
Professor Nolan confirmed Ireland was at the beginning of a fourth wave, adding: "The only things we don't know are how big and the extent to which it will translate into hospitalisations and severe disease."
