Some 5,000 people have so far received vaccines at walk-in clinics this weekend.
The head of the HSE, Paul Reid, says this means over 89% of adults are now partially vaccinated and more than 77% are fully vaccinated.
"We're getting there", he says in a tweet.
Our walk in vaccination centres continue today. So far this weekend another 5,000 people have availed of them to receive their first vaccination. Now over 89% of adults are partially vaccinated and over 77% fully. We're getting there. @HSELive
— Paul Reid (@paulreiddublin) August 8, 2021
The centres are open for a second weekend, following a successful campaign during the bank holiday - which saw over 30,000 people receive a vaccine.
The clinics are open to anyone who is set to receive their first dose of Pfizer who is aged 16 and over.
Those who already have an appointment booked can also use the walk-in facilities.
Mr Reid has previously said he expects Ireland's adult population to be fully vaccinated by the end of this month.
He told Newstalk on Friday: "Certainly during August we expect that the vast majority of the Irish adult population who come forward for a vaccine will have received it.
"We'll be certainly by the end of August/early September have completed the adult population.
"And probably about four weeks ahead of where we thought we would be".
On the portal for 12 to 15-year-olds, which opens on Thursday, he says vaccines should start early the following week.
While Mr Reid says confusion over COVID regulations is 'a reality that we deal with'.
"Our concern is that people do get distracted, get confused, get less committed and do drop their guard.
"And we are so close to completing this vaccination programme and so close to protecting so many people.
"But equally we're so close to losing it very quickly", he added.