Queues formed at vaccine centres in Ireland as children aged 12 to 15 received their jabs.
About 75,000 children in the age group had registered for a vaccine appointment by Saturday, 48 hours after the online portal opened to the cohort.
A number of centres administered vaccines to 12 to 15-year-olds on Friday but the main rollout began in earnest on Saturday.
The children, who need the consent of a parent or guardian to get vaccinated, are receiving Pfizer or Moderna jabs.
Bill Shelley, 14, and his 12-year-old sister Sarah were among those who queued in the pouring rain outside the vaccine centre at Citywest in Dublin on Saturday.
Afterwards their father Michael expressed his relief that his children had received their jabs.
“We’re very pleased, I’m delighted they’ve got their first vaccine,” he said.
“As parents, protecting them for their future health is one of the main reasons we’re here and keeping schools open is really important too.
“Really happy and really pleased – it went really well. We can’t thank the vaccinators and the team here enough.”
More than 80% of the adult population in Ireland is now fully vaccinated and about 90% partially vaccinated.
The Health Service Executive (HSE) has said it wants to vaccinate the 12-15 age group “rapidly and quickly”.