The Chief Medical Officer's warned as many as 400,000 people could be infected by Covid next month if action isn't taken.
That would mean nearly 13,000 cases every day in December.
Dr Tony Holohan says now is not the best time to be organising work place Christmas parties and the public should review any plans they have for socialising in the coming weeks.
It comes a day after the government announced it's latest mitigation measures which include a midnight curfew on hospitality and new rules on close contacts.
Dr Holohan says there would be huge pressure on the hospital systems if cases continue to rise at their current rate.
