It comes after hundreds of people were turned away from the Covid vaccination clinic at University College Dublin on Saturday morning after so many turned up for their booster shots.
The UCD Gerard Manley Hopkins Building vaccination centre was due to open its doors at 9am, but such was the queue that it opened at 7.50am.
The centre is administering booster vaccines to those aged between 50 and 69 and healthcare workers.
There were reports of people at the back of the queue remonstrating with Health Service Executive officials about being turned away.
Long queues were also reported at City Hall in Cork and at the CityWest vaccination centre in Dublin. There were queues at the vaccination centre in Kilkenny city an hour before it was due to open at 9am.
You can see the current wait times and the full list of walk-in vaccination centres at this link.