The Chief Clinical Officer with the Health Service Executive (HSE) has said the decision to pause the rollout of the AstraZeneca vaccine is the 'correct thing to do.'
Some 30,000 people will have their AstraZeneca vaccination appointments cancelled this week, as a result of the clinical pause on its rollout.
The advice came following information from the Norwegian Medicines Agency of four new reports of "serious blood clotting events" in adults after the vaccine had been administered.
The National Immunisation Advisory Committee (NIAC) made the deferral recommendation following discussions with the Health Products Regulatory Authority (HPRA).
A number of countries - including Denmark, Norway and Iceland - had already taken the decision to suspend its use over blood clotting concerns.
The World Health Organisation (WHO) is also investigating, but the company itself has said as recently as Friday there is "no evidence" its vaccine causes an increased risk of blood clots.
Dr Colm Henry, Chief Clinical Officer with the HSE, told Newstalk Breakfast confidence in any such programme is important.
"I think given the nature of these conditions - a small number, yes in younger people, but a rare clotting conditions - there may well be no association, no cause and effect proven with the vaccine.
"But I think it was a prudent and correct thing to do to pause temporarily - as other countries have done.
"I see Holland announced last night a similar move, a pause: this doesn't mean the vaccine is no longer considered safe, it means they're allowing the European Medicines Agency to take time this week to assess the evidence and see if there's any risk of these rare clotting events in vaccinated people against the general population".
Dr Henry said he expects an EMA assessment to be completed this week.
"Of course there will be people, maybe at this point in time, their confidence will be rattled.
"But let me say that I expect if the European Medicines Agency carries out a thorough review, which it will this week - and if they come up with an assessment saying that they don't see any association between these rare clotting events and the vaccine... when we come out of this, people will be I hope assured that we can stop whenever there's a signal such as this with a new vaccine programme, assess, pause and then move on once we have more robust evidence.
"And that's all that's happening here".
Asked how much this will set the vaccination programme back, he said it is not just about hitting targets.
"It means for those people who were due to have their vaccines this week in one or two groups, it means they won't be getting their vaccines this week.
"This is a disappointment to them and it's a setback to the programme.
"But the programme isn't just about numbers and targets - it's about the rollout of a safe, effective vaccine.
"And to do that... we must assure people that we're able to sit up, take notice and pause if necessary if there's a safety signal such as this.
"This does not mean we're stopping the vaccine".