All travellers entering Ireland from Friday 3 December, including those from the United Kingdom, will be required to show a negative result on a professionally administered antigen test 48 hours before arrival or on a PCR test 72 hours before arrival.
These new measures apply to all- whether fully vaccinated or not.
The new measures follow the emergence of the new Omicron variant which has prompted concern worldwide and Ireland has just recorded its first case of.
No self-adminisitered tests will be accepted.
The Government confirmed the new rules on Tuesday evening, with anyone who has recently recovered from Covid-19 or is fully vaccinated required to show proof of a certified negative antigen test 48 hours before arrival.
Children aged 11 and under would be exempt from the requirements.
In a statement, the Government said that travel operators would be required to carry out pre-boarding checks to ensure all passengers were following the new rules.
The Government will also introduce new legislation to re-establish mandatory hotel quarantine.
This will apply to anyone coming from one of seven southern African countries that are already subject to extra restrictions: Botswana, Eswantini, Lesotho, Mozambique, Namibia, South Africa and Zimbabwe.
Dr Gerald Barry, a virologist at University College Dublin, says that “using a once-off antigen test like this to stop Sars-CoV-2 coming into Ireland is scientifically unsound, and whoever came up with it should have a serious look at themselves”.
He added that he is “embarrassed for whoever thought this would be a good idea”. PCR testing is better, he believes, but the 72-hour predeparture testing window is too generous. “Shorten that and require it on the other side too. Consider false negatives as well as the chance of infection in the interim. Has nothing been learned? This is all just fluff to look like something is being done.”