The British pharmaceutical firm has warned that EU countries will receive less of the vaccine than anticipated in the coming months.
Minister for Health Stephen Donnelly has said that Ireland has been hit with a "real setback", as reports emerge that EU states will receive less AstraZeneca vaccines over the next month or so.
AstraZeneca warned on Friday that supplies of its coronavirus vaccine to Europe will be "lower than originally anticipated" due to reduced production at a manufacturing site.
AstraZeneca said in a statement that if EU approval is granted, the "initial volumes will be lower than anticipated".
An Taoiseach Micheál Martin also said that vaccinations for people over the age of 70 may be delayed as a result. He said that the situation has put us in a "real problem".
The company blamed "reduced yields at a manufacturing site within our European supply chain", without giving further details.
Speaking on Saturday morning, Donnelly said: "The news from AstraZeneca, which has advised the EU of a reduction in vaccine supply in Feb and March, is a real setback. The numbers are still tentative and AstraZeneca is due to provide more exact figures at a meeting early next week."
He said that he will provide an update "as soon as possible".
Ireland had expected to receive 600,000 doses of the AstraZeneca vaccine in the first quarter of the year.
