A further 764 cases of COVID-19 have been confirmed in the Republic, bringing the total number of cases here to 79,542.

Four more deaths have also been reported, brining the total number of deaths here to 2,158.

Of the 764 cases, 284 occurred in Dublin, 70 in Limerick, 52 in Donegal, 44 in Cork and 37 in Wexford. As of 2pm on Sunday, there were 233 hospital patients with COVID, 29 of whom were in ICU. There had been 15 additional hospitalisations in the previous 24 hours.

According to the Department of Health's chief medical officer, Dr Tony Holohan, "every indicator of disease severity is moving in the wrong direction, more rapidly than we had anticipated".

"We have particularly strong concerns about the prospect of inter-generational mixing around the festive season. On December 11, the seven-day incidence rate for people aged 19-44 was 106 per 100,000 population, by yesterday this rate had more than doubled to 217 per 100,000.

"If these younger people come into contact with their loved ones over the age of 65, we could see a spike in infections in this more vulnerable group. This would lead to very a serious pattern of disease, hospitalisations, ICU admissions and unnecessary deaths," Dr Holohan explained.

He urged people who have been socialising in the last few weeks to consider their Christmas plans carefully.

"Is it responsible to meet with your family over 65 later this week if you have not kept your contacts low? Should you cancel your plans?

"We have the very real prospect of COVID-19 vaccines on the horizon. Ensure that your loved ones stay alive to receive them, by keeping your distance from them if you have not restricted your movements to this point," he said.

While acknowledging how difficult this will be, he insisted that staying away from older family members this Christmas "will protect them and it would be an exceptional sacrifice made for the common good".

Meanwhile, a 48-hour ban on all flights arriving into Ireland from the UK, excluding Northern Ireland, has been announced by the Government. The ban will run from midnight on December 20 and will be reviewed on Tuesday at a Cabinet meeting.

The Government made the call in response to fears over a new strain of COVID-19 that has been identified in parts of England, and which has been found to spread more rapidly than usual.

For more information on the restrictions currently in place in Ireland, click here.