Chief medical officer Dr Tony Holohan has urged the public to limit their contacts over the coming days.
"Unfortunately, none of the indicators of this disease are showing encouraging signs," he said.
"Ireland now has the fastest growing incidence rate in the European Union.
"This Christmas, the best present you can give your loved ones is to strictly adhere to the public health advice.
"Make your Christmas safe, meaningful and memorable for the right reasons. Stay home, stay safe and stay well.
"Limit contact as much as you can and ensure you and your loved ones have a happy and safe Christmas."
A further eight deaths with Covid-19 were announced in Ireland on Christmas Eve, as gastro pubs and restaurants closed their doors.
Further restrictions aimed at stemming the spread of coronavirus are coming into effect on a phased basis as another 922 cases of the virus emerged.
There were busy scenes in the shopping districts of Dublin city centre on Thursday morning as final Christmas Eve preparations were made.
But the streets were noticeably quieter by early evening as the latest restrictions came into effect.
Contact services such as hairdressers and beauty salons also closed their doors.
Curbs will be phased in over the Christmas period, coming into full effect on January 1.
The Government has warned the restrictions could be in place for months.
Inter-county travel will be prohibited after December 26.
From January 1, no gatherings among households in private homes and gardens will be permitted.
The current measures that allow visits from two other households to a private dwelling or garden will end on December 27.
One other household will be allowed to visit up to December 31 before a ban on visitors, apart for essential purposes, comes into effect.
The adjustments from full Level 5 include non-essential retail being able to remain open, with guidance that shops do not run January sales.
Gyms, leisure centres and swimming pools can remain open for individual exercise, but no sports matches can take place apart from those at elite level.
Schools will stay open.
After 3pm on Christmas Eve, hotels will only be able to remain open for essential and non-tourism purposes.
Christmas religious services will be allowed but after December 25 services should return to an online format. Places of worship will remain open for private prayer.
