Health officials need to reconsider allowing the use of the AstraZeneca and Johnson & Johnson vaccines for younger people, the Taoiseach has said.
Micheál Martin believes the Delta variant has changed the "balance of risk" when it comes to using those vaccines, amid growing concerns over the Delta variant.
The National Immunisation Advisory Committee is set to examine changing the recommendations for use for younger age groups.
Currently, the AstraZeneca and J&J vaccines are only recommended for older age groups due to concerns over very rare cases of blood clotting.
Taoiseach Micheál Martin says that may need to change to keep up the pace of the roll-out through the summer.
He said: "That would really broaden the portfolio of vaccines available for July and August.
"I think the balance of risk has changed, so that's something that will be considered by the immunisation advisors to Government... to make sure we can protect people against the Delta variant."
Health officials have said there's a need to fully vaccinate people as quickly as possible to protect people against the variant.
More than 300,000 doses of vaccines are set to be administered this week and next.
However, the HSE has said vaccine rates will start slowing down in July, as the vaccine programme moves to younger age groups and delivering hundreds of thousands of second doses.
Additional reporting by Stephen McNeice
