Vaccination is preventing an "enormous" number of COVID-19 cases in Ireland, NPHET's Professor Philip Nolan says.
However, he's warning that the rising incidence rate nationally is a real concern.
Professor Nolan was speaking after more than 2,000 daily cases of the virus were reported for the first time since January.
Officials say the incidence rate is currently rising across all age groups and in all parts of the country.
It includes an increase in incidence among people aged over 65, although from "very low levels".
In a series of tweets, Professor Nolan said there have only been 21 days since the pandemic began where more than 2,000 cases were reported.
We have breached 2000 cases per day, 2074 cases today, the first time we have had more than 2000 cases since 21 January. We have had more than 2000 cases on only 21 of the 532 days since we reported the first case here. 1/9 pic.twitter.com/oNx9cz2H0x
— Professor Philip Nolan (@PhilipNolan_SFI) August 14, 2021
He said: "The real concern is that there is an underlying established pattern of exponential growth, with cases growing at about 3.7% per day since 19 June, and numbers in hospital growing at a similar rate, 4% per day, since early July.
"On 3 July we had 42 people in hospital, 14 in ICU, and were on average admitting 7 people to hospital and 1 to ICU each day; today there are 229 people in hospital, 43 in ICU, and on average 32 admissions per day to hospital and 4 to ICU."
He said the current situation is not sustainable, and caution is still needed even with effective vaccines.
He said: "We’re tired, and we wish it was all over, but it’s not. Look after each other."
Vaccination of people aged 12-15 is continuing today, after over 75,000 children registered for a vaccine within 48 hours.
