The HSE has confirmed that 18-49 year olds will have a choice of what vaccine they get.
NIAC is advising that under 50s are still offered an mRNA vaccine by the HSE, however if they want an earlier vaccination they can opt to get an AstraZeneca or Johnson and Johnson jab.
The registration portal will open for 30 to 34 year olds towards the end of next week.
HSE CEO Paul Reid says he's presented a plan to Government on how the latest NIAC advice would be embraced.
"We put forward to the minister...recommendations about how we'd go about it.
"But in essence, we'll be utilising all channels available to us - vaccination centres, pharmacies - and continuing down through the age cohorts, as we have been doing as well."
It's as the Taoiseach says new modifications to the vaccine programme wouldn’t have changed the decision to delay indoor dining.
The Government decided to pause the reopening following stark warnings from NPHET about the Delta variant.
However, this modelling didn’t take into account new advice to give the AstraZeneca and Jannsen vaccines to younger people.
But Micheál Martin says the delay was the right thing to do.
"I put the question to the opposition the other day, and I got no straight response.
"Noone in the opposition has said to me that we should proceed with the opening of indoor dining response.
"And you know why they wouldn't give me a straight response? Because they know there's only one response.
"We made the right decision to protect the progress we had made."