More than 1,300 community pharmacists will begin receiving supplies of COVID-19 vaccines from tomorrow.
They will start by giving the one-shot Johnson and Johnson inoculation to people over 50 to complete the vaccination of that age cohort.
The Pfizer jab will be used later in the programme.
HSE CEO Paul Reid said the initial commitment will see 60,000 vaccines distributed in boxes of 50 for each of the thousand pharmacies who will be partaking in the campaign.
He is "strongly encouraging" anyone in the over-50 age cohort who have not yet received their injection to come forward either through the process in pharmacies or by registering on the portal.
The vaccine portal is expected to open for those aged 30 to 39 in the coming days, with more than 3.1 million doses administered in Ireland so far.
Speaking to Máire Treasa Ní Cheallaigh on Newstalk Breakfast Weekends, Darragh O'Loughlin from the Irish Pharmacy Union said pharmacists "have been ready and waiting for months" to begin administering the vaccine.
"The HSE had consistently delayed getting pharmacies involved and at this stage, there are hundreds of pharmacies around the country ready to start vaccinating in the coming week as soon as vaccines start arriving into their pharmacy," he said.
"There are two pieces to it: The first is that the Janssen, or Johnson and Johnson vaccine, with be delivered to 700 or 800 pharmacies around the country in the coming days and those will be available for anyone over the age of 50 who hasn't already been vaccines, whether or not they registered on the HSE portal.
"If you're over 50 and haven't been vaccinated, you can now get the single-shot Janssen vaccine in a pharmacy.
"Then in a couple of weeks, a smaller number of pharmacies, mostly those that are not too close to vaccination centres, will have the Pfizer vaccine and they'll be using them just the same as the vaccination centres and GPs as part of the national vaccination programme."
Mr O'Loughlin added that anyone who has had their first dose of AstraZeneca, for example, will have to wait for their second dose and cannot go to a pharmacy for another dose of a different vaccine.
"The national vaccination programme has an IT system that pharmacists will be using to see who has already been vaccinated and who hasn't," he said.
Expanded role for pharmacists
He hopes that the rollout of the vaccine programme in pharmacies will lead to a more expanded role for pharmacists in Irish healthcare.
"We know that we have a superb GP system but our GPs are overwhelmed and the pandemic has really shown that," Mr O'Loughlin said.
"GPs have been working six and seven days a week between vaccination and COVID and a lot of primary, ordinary healthcare has suffered as a result.
"Pharmacists in other countries are heavily involved in primary healthcare but here we just haven't, for whatever reason, been using the potential of pharmacies.
He stated that the Department of Health and the HSE are "very conservative" and haven't wanted to make changes to how things are done.
"But Stephen Donnelly as Minister [for Health] has repeatedly said that he wants to see pharmacies deliver more primary care, he wants to see the HSE rolling out things like minor ailment treatment and so on through pharmacies," he added.
"We can only hope as the pandemic recedes that the Government actually makes good on the commitments they have made and the statements the Minister had made and actually does something for people this way."