A new report form the Organisation for Economic Cooperation and Development (OECD) has said many pupils, especially those from disadvantaged backgrounds, will have suffered long-term damage due to the Covid-19 pandemic.
The OECD's Director for Education and Skills said countries have responded "very differently with how they prioritise education" throughout the crisis.
Speaking on RTÉ's Morning Ireland, Andreas Schleicher said some countries kept schools open, particularly primary schools and kindergartens, while other countries immediately closed schools.
He said countries also differed with contingency plans - some were quick to put digital learning plans in place, while other countries "really struggled with that".
His main concern regarding Ireland, he said, was the closure of schools for young children.
"They are the ones that suffer most," Mr Schleicher said. "Because education is ... very much a social process where the contact between students and teachers is really important. For primary schools, I think Ireland is really at the high end, and you will see that in long-term consequences."
He said students who have access to good technology and parents who take the time to help them with their schoolwork will fare much better than those from disadvantaged backgrounds who do not have support.
For them, this experience has been "devastating" he said.
"Keep in mind that for many children, school is the most stable social environment", Mr Schleicher said. "It is a very, very important place, and suddenly that place is closed. That is, for disadvantaged students, a major breakdown."
Mr Schleicher said that while children rarely get sick from the virus, they are the ones most affected by public policy responses to the pandemic.
He said this is not just because of the interruption to their education, but to their social environment as well.
He said Ireland has "not seen that much investment" in making up for deficiencies, explaining that some countries have put a lot of resources into creating extra time for students and extending the school year.
