There were eight fully vaccinated people admitted to hospital with Covid-19 in the most recent 24-hour period, according to figures published by the HSE on Thursday morning.
A total of 86 people are in hospital with Covid, as of 8pm on Wednesday, with 22 patients in intensive care (ICU).
Letterkenny Hospital has the highest number of Covid-19 patients (12), followed by Mayo University Hospital (9) and St James’s Hospital in Dublin (8).
The HSE data shows there were eight fully vaccinated patients admitted with Covid-19 in the 24-hour period up to 8am on Wednesday.
Galway University Hospital admitted the highest number of fully vaccinated patients (4), followed by St James' Hospital (2). Letterkenny and Wexford Hospital each admitted one.
Seven of the patients were aged over 50, with one in the 19-49 age group.
More than 5.3 million Covid-19 vaccines have been administered to date, with 66 per cent of adults now fully vaccinated against Covid-19 and 80 per cent partially, HSE chief executive Paul Reid said on Thursday.
A further 1,378 cases of Covid-19 were confirmed in the Republic on Wednesday.
Deputy chief medical officer Dr Ronan Glynn has warned of a “significant increase” in hospital and intensive care admissions if incidence of Covid-19 continues to rise.
Meanwhile, Tánaiste Leo Varadkar said the Delta wave of Covid infections is “serious”, but the situation is different to previous waves because of the vaccine programme.
Speaking on Wednesday, he said: “This wave is serious and we need to ramp up the vaccination programme and that is what we are doing.
“We need to make sure we continue to improve test, trace and isolate, and that is what we are doing with antigen testing coming on board in the next week or so, we’ll be testing more people than ever before in the pandemic.
“We need to take this seriously, it is serious, but it is different because of the vaccination programme. The case fatality rate for Delta is one tenth what is was for Alpha because of the vaccine programme.”
