The head of the HSE says there is a 'very serious scaling up' of the COVID-19 booster campaign underway.
Paul Reid also says there has been a reduction in hospitalised cases, as 4,163 new cases were confirmed in Ireland on Thursday.
And Chief Medical Officer, Dr Tony Holohan, says things are beginning to stablise - albeit from a high level.
Mr Reid told The Hard Shoulder almost 900,000 boosters have been given so far.
"We're also resourcing up in terms of our booster and vaccination programmes.
"If you just take from last week, we've done 215,000 completed last week.
"Right now, today, of the booster campaign and the third dose for the immuno-compromised, 880,000 completed as of yesterday.
"So a very serious scaling up of it".
'Good hope from what we are seeing'
And he is hopeful of a continuing reduction in hospitalised cases.
"It seems to have stabilised, particularly over the past week, but stabilised at an extremely high level still.
"It's still 40% of our ICU bed capacity taken up with positive COVID patients - so we're stablised, it's given us a good relief.
"I want to take good hope from what we are seeing, but equally we need to have great caution and continue the measures that we are doing."
But he says they are looking to beyond Christmas.
"Our concern is - as we look through December/post-Christmas - if we were to sustain at those high levels of COVID patients heading into a flu season, and with the unknown of the Omicron variant... from our HSE perspective the concern what it might transform itself into in relation to hospitalisations.
"They're the unknown factors, which is why the public health measures are making a difference.
"And if we can sustain this really good progress in the public in the next few weeks, it makes a huge difference for us".
And he says almost half of all hospitalised cases are unvaccinated.
"93.5% of the adult population have been fully vaccinated, so about 6.5% of the adult population haven't been vaccinated.
"The majority of patients we have in hospital and ICU are adults, but yet what we do see is 48% of the hospitalised cases today are not fully vaccinated.
"That's a high disproportionate impact - and 50% of the ICU patients in hospital today have not been vaccinated at all".
And Mr Reid says he expects all healthcare workers to be vaccinated against the virus.
"I've made a very public call, throughout this whole programme, that as CEO I expect everybody, every healthcare worker to take it up.
"There's obviously marginal exceptions where it may not be possible for certain medical reasons.
"Where a healthcare worker hasn't taken it up... and putting a patient at risk, or putting the public at risk, they would be moved to a different role".