The Department of Health has reported 397 new cases of Covid-19.
There are 54 patients in hospital, with 16 being treated in intensive care, that is up two since yesterday.
In a statement, Chief Medical Officer Dr Tony Holohan said: "We are seeing a small but concerning increase in hospitalisations in recent days, coming 10-14 days after the five-day moving average of daily case numbers began to increase.
"This is a cause for concern and we will be monitoring it closely in the days and weeks ahead.
"Full vaccination is needed to protect against Covid-19, including the Delta variant. To protect yourselves and your loved ones, it is extremely important to take up the opportunity of being vaccinated and come forward for your second dose as soon as it is offered to you.
"The second vaccination is very effective at preventing both disease and hospitalisation."
The number of Irish adults who have been fully vaccinated now stands at 1.9 million.
In Northern Ireland, the Department of Health has reported 417 new positive cases of Covid-19 and no further deaths in the past 24 hours.
As of this morning, there were 37 Covid-positive patients in hospital, of whom five were in intensive care.
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To date, 2,079,758 vaccinations have been administered in Northern Ireland.
EU Digital Certificates due to be issued from next week
People who are fully vaccinated will receive their EU Digital Covid Certificates by either email or post from next week, under plans being finalised by the Government.
The cert is due to facilitate the return of non-essential international travel from 19 July, but could be expanded to include the reopening of indoor hospitality.
Minister for Transport Eamon Ryan said that the certificates will be sent out to the estimated 1.8 million people who are fully vaccinated.
Meanwhile, people in the 30 to 34 age group can register for an mRNA vaccine from tomorrow on the HSE vaccination portal, the Minister of Health has confirmed.
Those aged 34 can register for an mRNA (Pfizer or Moderna) jab from tomorrow, with 33-year-olds on Thursday, finishing with those aged 30 being allowed to register on Sunday.
The estimate for the number of unvaccinated people in the 18 to 34 age group is about 800,000.
