The Acting Chief Medical Officer has appealed to everyone to follow public health advice and only meet up with people from one other household at any given time.
Dr Ronan Glynn said the situation across the country is of "serious concern", and we must now limit the opportunities the virus has to spread from person to person.
The 470 new cases of Covid-19 reported yesterday is the highest daily number since the end of April.
198 cases were in Dublin, but the remaining 272 were spread across 24 other counties.
Dr Glynn said the situation nationally is now a matter of serious concern.
In Northern Ireland, a record daily rise of 934 positive cases of coronavirus was reported.
The head of NPHET's epidemiological modelling group, Professor Philip Nolan, said the virus has been growing exponentially since July.
He said if nothing changes we could see 1,200 or 1,300 cases per day by the end of the month.
However, he said this is not inevitable and that we can beat the virus by redoubling our efforts.
A Covid-19 briefing at the Department of Health last Thursday heard how the virus spread over the course of a weekend, resulting in 30 new confirmed cases.
The outbreak emanated from one index case over a weekend of socialising.