The AstraZeneca vaccine against Covid-19 will not be available in Ireland until mid-February, the Taoiseach has said.
The vaccine, described as a "game-changer" by Micheal Martin, is still subject to approval from the European Medicines Agency (EMA), which is expected on January 29.
Health Minister Stephen Donnelly had been in talks with AstraZeneca about securing early deliveries of the vaccine, so it could be rolled out as soon as EMA approval is secured.
But on Wednesday the Taoiseach confirmed this would not happen, saying it would still be a number of weeks before it arrives in Ireland.
He told the Dáil: "We have a much more comprehensive and detailed plan in terms of ramping up then the volume for the next phase (of the vaccine rollout).
"Particularly after the authorisation, hoping that'll go well, of the AstraZeneca vaccine, which should be on the 29th from the European Medicines Agency, and then for delivery in their timeline for mid-February."
Mr Martin said the vaccine rollout will be ramped up from February onwards.
He told the Dáil: "The key game changer for us in this, in terms of the availability of vaccines, will be AstraZeneca.
"We envisage significant ramping up particularly in February, March, April. And then May, June will be significant months as well, because the number of vaccines we will have will be very significant.
"It will no longer be a supply and demand issue, it will be the workforce issue. That work is well advanced."
The Taoiseach has indicated that the army, medical students and dental practitioners could be enlisted to assist with the rollout.
Mr Martin was responding to a question from independent TD Michael Lowry during Leaders' Questions on Wednesday.
Mr Lowry asked: "Has the Government considered using the resources of the army, and in particular its medical resource?
"Should we consider enlisting medical students? Should we consider even using dental practices?
"Should we consider using skilled laboratory technicians? I think we have to think outside the box, I think it has to be creative."
The Taoiseach replied: "Yes, I agree. Every category that the deputy has numerated there is being looked at, not just looked at, it's being worked on.
"This needs a national vaccinator workforce of a scale over and above existing hospital vaccinators, over and above GPs and pharmacists, and really drawing upon resources.
"Some who have retired for example, will be able to come forward. There will be vaccination centres across the country, in different communities.
"The national task force is working on this right now."