The rollout of vaccines to children aged five to 11 is expected to form part of an updated vaccination programme to be announced this week.
The over 40s are also set to be added to an accelerated booster plan amid fears over the Omicron variant.
The government is hoping to have 1,500,000 third doses administered by Christmas.
However its rollout has come in for criticism recently due to long delays at walk-in clinics.
Immunology Professor at Maynooth University Paul Moynagh says a new system is needed.
"Even an appointment based system based on when people become eligible, I think that would work very efficiently.
"The EMA came out last week and suggested that the booster should be given 6 months after the second dose, however they've now indicated that three months after the second dose is safe and effective."
