HSE calls for eligible people to come forward.
The HSE says up to half a million people who are re eligible for a booster vaccine have yet to come forward.
More than 2.6 million doses have so far been administered, with around 25,000 given out in the week up to Thursday.
A number of walk-in clinics are open this weekend, while people can also book an appointment or visit a pharmacy or GP.
Head of the HSE's Vaccination Programme, Damien McCallion, says it's important people come forward for their booster: