The latest development comes amid waning immunity in the face of high infection risk. Damien McCallion, who is overseeing the HSE booster roll-out, said he is waiting for guidance from the country's immunisation experts, who will decide on the queuing system for vaccines.
He expects the first deliveries of Pfizer vaccines for five to 11-year-olds later this month and in early January.
How soon they will be administered is a matter for recommendations from the National Immunisation Advisory Committee (Niac).
Niac advice "will dive into the priority" of when the HSE can start giving a first and second dose to children, he added.
The HSE is now building its defences in the face of the spread of the Delta virus and the new threat from the Omicron variant.
The priority for boosters to date is based on eligible people on grounds of older age and medical vulnerability.
The protection of the most vulnerable comes as it emerged the Omicron variant of Covid-19 appears to be reinfecting people at three times the rate of previous strains.
Experts in South Africa warned about its potential faster spread as public health officials and scientists from around the world closely monitor developments in the country where it was first identified.
The EU's public health agency, which is followed by Irish public health officials, warned that Omicron could cause more than half of all new Covid infections in Europe within the next few months.
The evidence is, however, that vaccines still appear to offer protection against serious illness. According to new evidence collected in South Africa by its National Institute for Communicable Diseases (NICD), the latest evidence suggests Omicron can evade immunity from infection with earlier variants and is causing reinfections at three times previous rates.
"We believe that previous infection does not provide protection from Omicron," said Anne von Gottberg, an expert at the NICD.
Figures show older age groups are already reaping the benefits of Covid booster shots, with a drop in infections in people over 65.
The HSE said last week cases fell by 14.6pc among the over-85s, 18.8pc in 75 to 84-year-olds and 8.3pc in the 65 to 74 age group amid evidence of booster shot benefits.
However, cases rose in two age groups, including the under-18s, whose infections rose by nearly 12pc, and 35 to 54-year-olds.
It comes as the HSE suggested that most people over 50 should be substantially boosted or have an appointment by the end of the year.
Mr McCallion said 85pc of the over-80s are boosted, 74pc of people in their 70s and around 100,000 of the 470,000 people aged 60 to 69 because of delays in becoming eligible.
Two-thirds of healthcare workers are boosted, 80pc of people with lowered immune systems and 11pc of the medically vulnerable whose vaccination started this week.
Around 880,000 booster shots and additional doses have been administered so far.
HSE chief Paul Reid said the situation in hospitals has stabilised, but they are on alert for a potential "turn" after Christmas if there is another spike in Covid admissions coupled with flu and winter illnesses.
It comes as 545 Covid-19 patients were in hospital yesterday, a fall of 33 since Wednesday.
The number of patients in intensive care was stable at 117.
There were 4,163 new cases of the virus reported yesterday.