Chief medical officer Dr Tony Holohan has warned that people socialising pose a threat to the gains made in fighting Covid-19.
He issued a stark warning yesterday saying "we are seeing a number of things which concern us", as another 378 new cases were recorded and one additional death.
"There are examples of small numbers of people congregating for social purposes and simply ignoring the important public health messages. They are putting our collective progress at risk," he said.
"We are also seeing a number of outbreaks across the country. These include outbreaks in association with funerals.
"We understand that this is a difficult time for families, but it is really important that we do everything we can to avoid the circumstances which promote transmission of the virus.
"There have also been outbreaks associated with workplace settings.
"As we head into a new working week, we need to stay at home other than for essential reasons, and for personal exercise within 5km.
"Anyone who can work from home should work from home," he added.
"The average daily five-day case count is rising and is now over 400 per day. This is a worrying development which has persisted for the last few days."
Of the cases notified yesterday by the Health Protection Surveillance Centre, 124 were in Dublin, 34 in Donegal, 23 in Louth, 19 in Cork, 19 in Limerick and the remaining cases were spread across 20 other counties.
Meanwhile, Tadgh Daly, CEO of Nursing Homes Ireland, told the Herald, that clear guidance is required in relation to the issue of visits to residents at Christmas.
"Ultimately, what we want to do is explore all the options. I think all of us should work towards ensuring safe visits by at least one person," he said.
"We are just conscious, like anybody, that Christmas is a unique time.
"We want to be planning, you need a lead-in time, but also we need public health support."
Mr Daly said there must be a Government-led communication plan so that everybody is clear and knows what the position is.
He said many of his nursing home members have built well-ventilated and heated visitor areas.
The challenge will be in some parts of the country, if there is a high level of community transmission, to be in a position to open nursing homes to visits, Mr Daly said.
"So it is a bit early, but that said, we do need to look at what all those options are ultimately."
Speaking on RTÉ Radio 1 This Week programme yesterday, Dr Gabriel Scally, president of Epidemiology and Public Health at the Royal Society of Medicine, said: "It would be great if people could see their relatives, even at a distance of some metres at Christmas.
"The Republic has done extremely well in this second wave compared to most of the rest of Europe, and that bodes well, and if that continues for the next couple of weeks and the numbers of cases stay down."
However, he said: "The last thing we want to do is give anyone a Christmas present of Covid-19."
In relation to the potential lifting of Level 5 restrictions in two weeks' time he sounded a note of caution.
"I think our experience with alcohol and Covid-19 is not a happy experience, and in the run-up to Christmas I think one would need to be extremely cautious before indoor premises serving alcohol were permitted to have any sort of opening hours," he said.
He also said he didn't think travel should be on the agenda this Christmas.
"We know this virus travels very well and having people flowing in and out of countries and through airports and all the other travel it involves is a recipe for disaster," he warned.
Professor Mary Horgan, president of the Royal College of Physicians of Ireland, told the Herald: "While I certainly would hope that Level 5 restrictions will be lifted, you would hope that it would be at least Level 3 or Level 3-plus which is opening retail, hairdressers, but maybe limiting gatherings within houses, because that seems to be a big driver.
"It is really important that we are protecting lives and livelihoods and that is what the World Health Organisation would say all the time."