Members of the public were asked not attend two Covid-19 drop-in vaccination centres in Dublin after both reached capacity this morning.
People aged over 50 who do not have underlying health conditions can receive a booster vaccination dose as of today (Thursday).
Ireland East Hospital Group confirmed in excess of 600 people arrived at a drop-in vaccination clinic at UCD early this morning.
The booster vaccine clinic is offering shots to those aged 50 to 69 and all healthcare workers from 8am to 10am.
However, at 8.40am the HSE wrote on Twitter that there were “very large queing times” at the UCD clinic and said “please do not go there as the centre is at capacity”.
Photographs circulating on social media appeared to show hundreds of people queuing from before dawn.
In a post on Twitter, the Health Service Executive advised people not to attend the UCD clinic due to “very large queuing times“, adding that the centre was at capacity.
It also said the walk-in clinic at Croke Park had reached full capacity for the morning.
A number of drop-in clinics for booster vaccines, as well as first and second doses, are in operation today.