The HSE's online portal will open for 34-year-olds to register for a Covid-19 vaccine tomorrow.
The application process will continue with 33 year olds on Thursday, down to 30-year-olds on Sunday.
Health Minister Stephen Donnelly says appointments will be given out within days of registering.
Over half of the adult population is now fully vaccinated against Covid 19.
69 per cent have received a first dose while 4.4 million vaccines have been administered.
It comes as concerns continue about the Delta variant which now accounts for 70 per cent of cases.
Health Minister, Stephen Donnelly, says some of NPHET initial predictions are unfolding.
"We've got to do everything we can to avoid the worst scenarios we saw from NPHET.
"At this point it's very hard to predict what will happen, but what I will say is that the initial uptick in cases that was predicted by the modelling team is happening.
"We're seeing it in the national figures, we're seeing the R number go up, we're seeing the 14 day case numbers go up."
