The AstraZeneca and Johnson & Johnson vaccines may be given out to younger people under new plans to be discussed at Cabinet.
Ministers are meeting this afternoon to discuss further changes to the country's vaccination programme.
Last week, the National Immunisation Advisory Committee (NIAC) said the AstraZeneca and Johnson & Johnson (J&J) vaccines should only be used in people over the age of 50.
However, the committee said the limit should not apply when other vaccines are not available.
The Irish Times reports that ministers will discuss offering the jabs to people in their 40s to ensure the rollout is not delayed – and the HSE is not left with unused supply while people are still waiting to be vaccinated.
Vaccine registration is this week opening up for people in their 50s – starting with 59-year-olds who can register from this morning.
Officials do not expect to reach the 40-49 cohort for a number of weeks yet.
As of Saturday, more than 1.5 million vaccine doses had been administered in Ireland – including 1.1 million first doses.
Yesterday, 453 new coronavirus cases were reported in Ireland – bringing the national total past 250,000.
There were 129 COVID-19 patients in Irish hospitals – a 30% decrease on the same day last week.
Meanwhile, there were 40 in intensive care – six fewer than the previous Sunday.