The Chief Medical Officer has voiced concern about the rising incidence of Covid-19 across the country.
He spoke as 2,193 cases of the virus were confirmed and the number of Covid patients in hospital surpassed 500.
There are currently 513 Covid patients in hospital, of which 97 are in ICU.
This is an increase of 16 hospitalisations on the same time yesterday.
It is the first time since early March that more than 500 patients with Covid-19 are being treated in hospitals around the country.
The number of people being treated for Covid-19 in ICU is at its highest number since March 9.
Dr Tony Holohan said as the numbers continue to rise in the community the primary focus must be to protect the most vulnerable among our population.
A substantial amount of those being hospitalised and admitted to intensive care are not fully vaccinated, he said.
This is placing frontline healthcare services, including non-Covid care under significant pressure, Dr Holohan warned.
Breaking the chains of transmission is essential when it comes to the Delta variant.
Those who experience symptoms of the virus, even those who are fully vaccinated, are advised to stay at home, isolate from others and arrange a free test immediately.
Once again, Dr Holohan urged those who have not yet availed of the Covid-19 vaccine to do so at the earliest opportunity.
“The vaccine, our best defence against Covid-19, is not the only tool we have to drive down the spread of the disease.
"Please continue to regularly wash your hands, cover your coughs and sneezes, open windows and ensure spaces are well ventilated, wear masks on public transport, shops, indoor workplaces and crowded outdoor areas, and by keeping a safe 2m distance from others as much as possible."
Professor of Immunology at Maynooth University, Paul Moynagh, has said Covid case numbers are likely to get worse before they get better.
As people move further from the time they received their second dose of vaccine, some are becoming more susceptible to infection.
He said the increase in socialisation and the time of year as we head into the winter months are among the reasons for some of the breakthrough infections that are being detected.
"I think the numbers are likely to increase but it is very, very difficult to be precise about how numbers are going to go," said Prof Moynagh.
It would have a significant effect on the case numbers if those who have yet to take the Covid vaccine could be encouraged or persuaded to get vaccinated.
The HSE says it has seen a slight increase in the uptake of Covid-19 vaccinations over the past number of days.
Damien McCallion, head of the HSE's national vaccination programme, said they have seen some positive figures in recent days, noting that since Thursday, there has been an increase of between 800 to 1,000 coming forward for a vaccine per day to about 2,000 people per day.
Mr McCallion said they were running a campaign over the next 10 days to encourage those who are unvaccinated to come forward.
The campaign aims to provide people with information in relation to the Covid-19 vaccine.
There will be specific campaigns targeting groups that are particularly vulnerable, including the medically vulnerable.
According to Mr McCallion, more than 60% of those in ICU are currently unvaccinated.