Health officials are expecting a high level of uptake for Covid-19 vaccines among 12-15 year olds.
The HSE is to start offering jabs to children that age within the next two weeks.
The 6 millionth dose will be administered in the coming days as the rollout continues.
Dr Ray Walley, member of the GP Advisory Committee to the HSE, says vaccinating younger people is crucial.
"What we're trying to do is achieve a herd immunity in 85-90% of the population.
"We know from focus groups and talking to parents and meeting children that they want to play their part in this.
"They want to get vaccinated to be safe for themselves, and they want to get vaccinated to be safe for their friends, their grandparents and their parents."
