Young people are making "extraordinary efforts" to shore up Ireland's vaccine "floodwall", according to the HSE's chief clinical officer Dr Colm Henry.
He says some walk-in vaccination centres had to open early to deal with the demand over the weekend.
Over 18,000 people have been vaccinated at the walk-in clinics so far this long weekend - including 10,000 on Saturday and another 8,000 on Sunday.
Dr Henry told Lunchtime Live the level of uptake "went way beyond our expectations".
He said: “It’s not just the numbers - it’s the enthusiasm and determination of these people to get vaccinated. It really adds to that extraordinary sense of solidarity in this country.
“The scenes of enthusiasm and general positivity was just something really positive to be part of.”
Dr Henry said he was at a centre in Cork that had to open its doors early to cater for the higher than expected level of demand.
The vaccine centres are currently only for first doses, with people being offered a second appointment at a centre close to their home address.
Dr Henry said: "Obviously we’ll be reviewing this after the weekend, given it went way beyond our expectations.
"We’ll see if we can replicate this or have a more flexible programme: anything we can to do improve uptake and ensure people complete their vaccination programme.”
'Envy of Europe'
Around half of those vaccinated at the centres this weekend have been teenagers aged 16-17.
Dr Henry said Ireland's now in the top five in the EU in terms of the vaccine rollout, but we're the "envy of Europe" in terms of the levels of uptake among different age groups.
Noting that vaccines are building up a "floodwall" in protecting communities against COVID-19, he noted: “This weekend we’ve seen the extraordinary efforts of young people to shore up that floodwall."
As we head into August and look towards the autumn, Dr Henry said the COVID-19 situation in any country can change very quickly.
However, he said there's "every reason to be optimistic" about Ireland's current position - especially compared to last winter.
He said: “The [trends in the] number of cases and hospitalisations… all are verging towards the more positive than negative at this stage.”
Vaccine registration for children aged 12-15 will begin within the next two weeks.
Dr Henry said the National Immunisation Advisory Committee (NIAC) has concluded that the benefits of the vaccine outweigh the risks for young people.
He said: “To assure people… [Dr Karina Butler and NIAC] have pored over the figures and evidence internationally.
"Their focus has been entirely on what the best advice to give to children and their parents is.”