Worrying Covid-19 clusters are emerging in direct provision centres, among Travellers, and in meat plants, according to the National Public Health Emergency Team (NPHET).
Fresh concerns have been raised about the spread of the virus by NPHET, in advice it has given to the Government.
The advice, which has just been published, is what the Government used when deciding to delay Phase 4.
The public health doctors said "concerning" outbreaks have occurred in direct provision centres, among the Traveller community, and in meat factories in the past week.
There have 37 new clusters, with 21 in Direct Provision Centres, involving 235 people.
21 new cases from two clusters have been found in the Traveller community, with two outbreaks in meat factories involving 47 new cases.
NPHET also warns there has been a shift in cases from the greater Dublin area to other counties in the past 10 days.
It recommends pubs and restaurants should close by 10.30pm, but the Government has changed this to 11pm.
It also said it should be mandatory for staff to wear face coverings if not behind protective glass, and all customers should sit at tables, not at the bar.