There have been a further 20,909 confirmed cases of COVID-19 in Ireland.
Latest figures show 1,055 patients are hospitalised with the virus - 92 of whom are in ICU.
There has been a total of 6,035 deaths related to COVID-19 here - including 83 newly-notified deaths in the past week.
The five-day moving average of cases stands at 22,323.
Chief Medical Officer Dr Tony Holohan says there are "positive indicators" over Omicron.
"Today's changes to the public health management of COVID-19 cases and close contacts are framed in light of available evidence, expert views and the international experience of COVID-19 - including the recently published guidance from ECDC.
"The Omicron variant of COVID-19 is continuing to have a significant impact on all areas of our society and economy due to its increased growth advantage compared to Delta.
"There are some early, positive indicators however, that suggest infection from Omicron results in less severe illness and reduced requirement for care in hospital."
He adds that the measures are more proportionate to current infection levels.
"It is important to note that the changes announced today cover a range of measures from self-isolation and restriction of movements to mask wearing and testing.
"These measures are more proportionate to the current level of infection and the impact it is having.
"In particular, while we are reducing the requirement to self-isolate and restrict movements for cases and close contacts respectively, we are strengthening guidance relating to mask wearing and reduced social contact for the full 10 days following diagnosis or last known close contact.
"These measures are intended to maintain our protection of public health while reducing pressure on the health service and enabling the continued operation of other economic and social sectors in society, including essential services."