The chief medical officer has welcomed the news that the Covid-19 vaccine will soon be made available to children aged 5 to 11.
Dr Tony Holohan said the move is a "significant positive step".
His comments come as the Department of Health confirms a further 4,152 cases of Covid-19 in Ireland.
As of Wednesday morning, there were 543 people in hospitals with the virus, up 38 since yesterday, with 118 patients in intensive care units, up one.
There has been a total of 5,788 deaths related to Covid-19 notified in Ireland.
Dr Holohan said new data on the Omicron variant are emerging every day and that scientists need time to complete studies and interpret the results.
"Our high incidence of disease from COVID-19 is driven by the Delta variant.
"We know how to break the chains of transmission of Covid-19 – these measures have worked against previous variants of Covid-19, they can successfully suppress transmission of the Delta variant and we are optimistic that they will work against the Omicron variant."
He added: "Vaccination remains one of the best ways to protect ourselves from severe illness and death from Covid-19."
In the North, a further 1,933 positive Covid cases have been reported, along with five further deaths.
Three doses of the Pfizer/BioNTech Covid-19 vaccine appear to neutralise the new Omicron variant, according to preliminary studies.
Pfizer and BioNTech said the antibody levels reached with three doses of the vaccine were just as good as for two doses against the original Wuhan strain of the virus, which have already been shown to offer high levels of protection.
Laboratory work found that two doses of the vaccine resulted in a significantly reduced effectiveness against Omicron, suggesting people can still get infected with the variant.
However, the firms said two jabs are still expected to work against severe disease owing to how the body uses a range of immune cells, including T cells, for protection.
The work showed that, when it comes to boosters, three doses of the vaccine increased neutralising antibody titers against Omicron in people’s blood 25-fold compared with two doses.
Pfizer and BioNTech said this showed that booster doses could offer good protection against Omicron.
The National Immunisation Advisory Committee (Niac) has recommended that Covid-19 vaccinations be offered to children aged five to 11 years.
The advice has been given to Government today, meaning approximately 480,000 primary school children will now be offered a vaccine.
The vaccine for this group is a lower dose and is expected to arrive in the country soon.
It is likely to be January when the rollout for this age group begins, while some children with an underlying medical condition or living with someone who is immunocompromised, may receive their vaccine this month.
Up to now, vaccines had only been approved for use in people aged 12 and older.
Health Minister Stephen Donnelly said today's announcement "is another positive step forward in our country’s response to the Covid-19 pandemic."
Mr Donnelly said extending vaccination to this age group will "offer another layer of protection to our children, and to those around them."
The vaccine given to children called Comirnaty, developed by Pfizer/BioNTech, is a weaker dose of the vaccine given to adults and will be given as a two-dose schedule, three weeks apart.
Speaking on the booster vaccine, which has now been extended to those over 50, Mr Donnelly told people do not hesitate in getting their third shot.
“We are already beginning to see a significant reduction in incidence of Covid-19 infection in the over 75 age group, where people have been taking up the offer of a third dose of a Covid-19 vaccine in high numbers.
"This is really good news and shows the benefits of receiving a third/booster dose.
“It is vital that all of us prioritise our booster appointments as soon as we receive them or make the time to attend a walk-in vaccination clinic if that option is available.”