A Minister of State has said vaccine delays are the cost of 'putting them out as you get them'.
Ossian Smyth, Minister of State for Public Procurement and eGovernment, told The Hard Shoulder they are distributing the vaccines as fast as they get them.
"The HSE has had some operational problems this week, and the Taoiseach did acknowledge in the Dáil the frustration felt by GPs and by their patients.
"It is our policy to distribute the vaccines as fast as we get them.
"And what that means is in a situation where there is a shortage, where there is a deferred delivery, it can mean that we have a bumpy week - or we have a week that's short - and that we have to make it up in a week where we have extra supply.
"And we do have the vaccines available to make up for that. So I guess that's the cost of putting them out as you get them".
While Minister Smyth said he is confident the HSE can deliver on the vaccine rollout.
"They have experience in mass vaccination because they do the flu vaccine every year, they have experience doing mass logistical exercises as they've done with the testing regime.
"So I've every confidence that they're going to do this.
"And it is difficult with the over 85s - when you're with those cohorts and people who are vulnerable, it is harder to move them around.
"The efficiency comes from when we move to the mass cohorts, and we're saying to people 'You need to go to Aviva Stadium, or you need to go to Citywest at this time and you join a large queue' - that's where you get the giant, 100 people who are vaccinating people in parallel, that's where you get the efficiency.
"Of course it's going to be slower with the more vulnerable cohorts.
"But is is absolutely the right policy to deal with the people who are most vulnerable first, and the healthcare workers who are most likely to spread it".
He also said he was "very confident and very positive" as more vaccines come on stream.
"We have delivery schedules - and this is the hardest part - that our delivery schedules are not that granular.
"We've got them for the second quarter, we don't know what they're going to be in the third quarter.
"Some of the drugs that we're planning to use have not yet been authorised".
He said the the Johnson & Johnson drug is expected to be approved within the next week.
It comes as GPs said they are frustrated with the vaccine rollout, and a lack of communication from the Health Service Executive (HSE).
Dr Marie Scully earlier told Lunchtime Live: "I am in communication with lots of my colleagues both nationally and locally, and it isn't the same for a lot of practices who are very upset with the level of communication the HSE and them, with cold chain deliveries, with people being promised one lot of vaccines [and] not getting them, getting more than they ordered, getting less then they ordered: having no contact at all".
Dr Scully said some practices have had no communication "despite constant ringing and e-mailing.
"It's really frustrating".
She said there is a dedicated HSE e-mail for GPs on vaccines "but when you e-mail you get no response at all".
And she said a subsequent dedicated vaccine phone line "either that doesn't answer, or you get somebody answering who says 'We'll take your details and ring you back' and they never ring you back."
Tánaiste Leo Varadkar also admitted there have been issues with the vaccine rollout plan.
Speaking in the Dáil, he blamed an under-delivery from AstraZeneca for missing last week's target of 100,000 vaccinations.
Fine Gael and Fianna Fáil TDs also criticised the speed of the vaccine rollout at their respective parliamentary party meetings on Wednesday night.
Mr Varadkar said some of that criticism is justified.
"I appreciate that there have been some issues and have been some delays.
"A consignment of 25,000 AstraZeneca vaccines that we had expected to arrive last week did not arrive at short notice.
"We're told it will arrive before the end of the month, allowing us to catch up.
"So there will be weeks where we fall behind target, there will be weeks where we go ahead of target".