Dr Tony Holohan has warned that people should opt to shop online where they can as the Omicron variant spreads rapidly through the community.
Thousands of people are at home isolating this Christmas after picking up the infection, and over 11,000 cases were reported on Friday.
This is the highest ever daily cases figures that have been reported since the start of the pandemic, while there are now 393 people in hospital, of which 89 are in ICU.
In an effort to flatten the curve, the CMO said people shouldn't be heading to crowded shops after Christmas.
He said: "Avoid crowded places including retail environments.
"Choose to shop online where possible, queue outside and leave any retail environment that does not feel safe and that is not adhering to the public health guidance – implementing social distancing measures and queuing system, limiting numbers instore and staff wearing masks correctly - covering nose, mouth and chin.
"It is important that all of us continue to reduce our contacts and avoid crowded places, to the greatest extent possible, as we see the Omicron variant become the dominant variant of Covid-19 in Ireland.
"We know that this variant is more transmissible than even the highly transmissible Delta variant. As such, please do not socialise or meet indoors with people from other households."
In terms of what to do if you test positive over the festive season, the CMO says: "If someone in the household receives a “detected” or “positive” test result either via a PCR test or an antigen test, then all members of the household should restrict their movements and not attend work or socialise with others.
"Even though we recognise that it is very difficult at this time of year to stay away from loved ones, it is really important that anyone who receives confirmation of a confirmed #COVID19 infection self-isolate for ten days.
"If you are identified as a close contact and have received a booster dose of #COVID19 vaccine, then you should restrict your movements for five days. If you have not yet been boosted, you should restrict your movements for ten days. More information on http://hse.ie.”
