Large queues at vaccination centres saw people waiting for hours in freezing weather conditions for booster jabs.
At Cork City Hall, hundreds of people queued around the block for walk-ins and scheduled appointments.
Booster jabs are being offered this weekend to healthcare workers and those aged between 60 and 69, with anyone over 12 years of age also encouraged to attend for a first or second dose of the Pfizer vaccine.
John Scriven, 75, was among those in the queue for a booster.
Mr Scriven waited patiently in the cold despite having an appointment.
“I’ve been out here now for more than an hour. Older people should be looked after and go straight through, rather than have to stand out in the cold.
“I think everybody should get their booster, especially with the new variant after popping up in South Africa,” he said.
For walk-ins, some waited up to two hours for their jab.
Kay and Billy Fitzgerald, aged 66 and 67, went for a walk-in booster rather than wait for a text appointment.
“The queue isn’t great but it has to be done. We would be anxious about Covid because we mind our grandkids, and we want to get the booster to have that extra layer,” said Ms Fitzgerald.
At the vaccination centre exit, Mark Turner, 60, had just received a booster after a two-hour wait.
“It was a bit of a shame to go all the way around the block and find there was another queue with appointments, and obviously those people were annoyed too because they were missing their appointment times,” he said.
Hazel Kelly, 55, a healthcare worker, had an appointment for a booster.
“I’m absolutely perished,” she said, adding that it was “ridiculous” that healthcare workers and those with scheduled appointments were not prioritised over walk-ins.
Sandra Yeomans, 31, had also come for a walk-in booster.
“I’m a healthcare worker, and I think the booster is important to protect patients and colleagues. A lot of our colleagues are getting sick, we got our vaccines in January so I think immunity is waning,” she said.
“It’s very busy in the hospitals, we’re under a lot of pressure and staffing levels aren't great. Hopefully, boosters will help,” she added.
A spokesperson for the HSE said today that they were making every effort possible to manage increasing demand at vaccination centres in Dublin and Cork.
“There was strong interest from walk-ins today at our Cork City Hall vaccination centre. We have seen unprecedented take up from walk-ins and that is very positive. This is leading to some delays but we are working to minimise these as much as possible,” the spokesperson said.
In Dublin, the HSE apologised after many people were left waiting five hours for boosters at Citywest vaccination centre.
The HSE said it faced “unprecedented demand” at the centre due to a scheduling error that saw people called for vaccination who were not eligible.