The Health Minister has urged people to cut back on social gatherings and reduce social contacts "just for a while".
It comes as 551 people are in hospital, including 83 in ICU, over half of whom are not vaccinated.
The country's 14-day incidence rate of COVID-19 has more than doubled over the past month, with more than 3,000 cases being reported daily over the last week.
Stephen Donnelly said COVID-19 is spreading rapidly among young people.
He said: "In the age groups from around 35 down - particularly for the 19-24-year-olds - the lines on the graph are almost vertical: cases are rising really, really quickly.
"Everybody [should] just reduce their discretionary social contacts - just for a while. All of just need to play our part."
Meanwhile, the HSE today said they're starting to see a fall-off in COVID-19 cases among older people - suggesting that "may well be due" to booster vaccines.
Dr Colm Henry said: “Particularly in those over-85s and over-65s we are seeing a fall-off in cases, bucking the trend we are seeing in younger age groups.
“So, it is a more complex story than just the cases going up alone."
