The Department of Education has said the reopening of schools has led to no significant change in the proportion of school-aged children contracting Covid-19.
It said data shows that the proportion of cases found among the four- to 18-year-old age group has remained steady since August, at between 14.1% and 14.3% of all Covid cases.
The department said this supports the hypothesis that children are not at increased risk from Covid-19 in the school setting.
According to the new figures, 5,890 school students and teachers have been involved in mass testing which is or has been taking place in 236 schools around the country.
The department said testing at the 236 schools has led to the detection of an additional 90 cases of the virus. This equates to a rate of 1.5%. The comparable rate when similar mass testing has taken place in the community stands at 6%.
The data measures the situation up to last Tuesday.
In a statement, the department said public health officials were "casting their net wide" with mass testing in schools to assess evidence of levels of transmission, and that this low rate supported other evidence that schools are "safe environments".
The Department of Education said "no decision has been taken" to extend school closures over the mid-term break.
It was responding to a newspaper claim that a decision to extend the mid-term by one week had been discussed by Cabinet and was expected.
Speaking prior to a meeting of the Cabinet sub-committee on Covid-19 with NPHET this evening, Minister for Finance Paschal Donohoe said no such proposal had been put to him yet.
The meeting agreed to introduce graduated fines for breaches of Covid rules but concluded without the issue of schools being discussed.
Earlier, a Department of Education spokesperson said keeping schools safely open for children and staff was a key priority, and had been given careful consideration by NPHET, which had recommended that schools remain open at the present time, even given the current trajectory of the disease.
"The Irish experience to date supports the current international position that schools are low risk environments for Covid-19 and are not key drivers of transmission," the spokesperson said.
The department earlier said that many cases of Covid-19 linked to schools in Ireland have been found to have exposure to the disease outside of the school environment, for example, in a household or social setting.
Similarly, where testing of close contacts (of confirmed cases linked to the school) identifies additional cases of Covid-19, many of these are found to have had exposure to the disease outside of the school.
It said there have been relatively few instances where transmission of Covid-19 within a school is strongly suspected by HSE Public Health.
Schools are due to close for the mid-term at the end of the month.
School management and trade union bodies say there have been no discussions or proposals around any such closures. But one source described the suggestion as logical.
However, the Children's Rights Alliance has expressed dismay, saying the impact of closure on vulnerable children should make any such move a last resort.
Tanya Ward of the alliance said public health officials had assured the organisation that the reopening of schools was not associated with increases in rates of infection.
"We are concerned that when schools did close we saw pupil disengagement rates of 30%," Ms Ward told RTÉ News.
"At this state when the evidence is telling us that schools are not where the problem is, and when we know what the impact of closure is on vulnerable children it has to be a measure of last resort."
"The strategy to date has been to keep the schools open at all cost, and the suggestion that they close is not at all in line with the evidence led position of NPHET," she said.
Ms Ward said schools should be supported in continuing to deal with local outbreaks through part or full closures as required.
School closures would be 'illogical' - ASTI
The General Secretary of the ASTI said it is "unacceptable" that teachers, management bodies, students and parents are reading reports about a proposal to extend the midterm break by an additional week as part of the effort to curb Covid-19.
Speaking on RTÉ's Drivetime, Kieran Christie, said it would be "illogical" to close schools for an extra week at Halloween, "unless there was a plan to do similar actions in wider society".
He said the ASTI is committed to schools remaining open, and members will continue to be guided by public health advice.
Speaking on the same programme, Fianna Fáil TD John Lahart said extending the closure of schools would create "so much other confusion in the society that it would have to be evidenced-based".
He said: "We need to stick to the plan, and any decision that is made needs to have to be evidenced based."
Mr Lahart appealed for people not to leak information due to the anxiety that it can cause at this time.
He added the Fianna Fáil parliamentary party this week discussed the possibility of closing schools a little earlier ahead of Christmas to allow grandchildren to quarantine ahead of visiting older or vulnerable relatives.
This morning, primary teachers' union, the INTO, said it was "imperative that when significant decisions are being made that the education stakeholders are consulted and given due notice of the outcomes so we can manage any potential disruption to our primary schools".
It reiterated calls for an urgent review of the public health advice on schools to determine the necessary level of protocols, protections and precautionary measures needed when the level of infection is very high in a community.
The union said there were alternatives to closure and to supporting learning remotely, such as partial opening where half of each class attends school on a rota basis.
The Teachers' Union of Ireland General Secretary Michael Gillespie said the TUI noted the speculation in relation to potential changes to the school calendar.
"Clearly, all education stakeholders must be fully consulted in any such move to allow for any disruption to regular school business to be planned for," Mr Gillespie added.