The most informative school study from an Irish perspective is probably the large scale study in Belgium.

It was conducted by Sciensano (Belgium's National Health Institute) and is arguably the most comprehensive study of its type in Europe, with most relevance to Ireland.

It's particularly relevant to Ireland, as unlike other countries, Belgium reopened schools in May.

At time of reopening their 14-day incidence was 44.6 per 100,000. Ireland are nearly half as much at 25.6 per 100,000 today.

So it's more instructive than S. Korea comparisons.

School confirmed cases (to June 28th, Belgium):

Children: 270
Teachers: 108

Close contacts of confirmed cases quarantined:

Children: 4,472
Teachers: 243

So on average, teachers had 2 close contacts, children had 16 close contacts.

That obviously makes sense.

Children play with their friends on green, they have people they sit beside in class, brothers/sisters etc so that amount of close contacts is probably about normal.

For teachers to only have 2 is impressive but it's currently 5 for adults here.

Those children returned to school in class sizes that are 4 pupils less than Irish class sizes (primary).

Conditions:

Children under 12: No masks
Children over 12: Mask
Teacher: Mask
Pods: Yes
Bubble: Yes
Staggered times leaving school: Yes

The absolute key finding of the study:

Children (270 cases):

Infected at home: 234
Infected at school: 36

Teachers (108 cases):

Infected at home: 97
Infected at school: 11

The definition of "at home" can mean Tesco, on the train etc - outside of school.

What that means in practice is of the 4,715 close contacts, only 1% (47) were secondary infections.

That's an attack rate of 1% and validates the large Australian study which found a secondary attack rate of 1.2%.

This should massively reassure people on a couple of levels.

A key concern I see is people worried that their asymptomatic children will infect parents or grandparents.

What the Belgian and Australian studies show, is the secondary attack rates are tiny and that onward transmission is very low.

This should be reassuring.

Melbourne and Sydney had 60 school outbreaks in past 4 weeks, Berlin had 41 school outbreaks, Aarhus (Denmark) I believe is at 34 outbreaks...

There is no country I can find that hasn't had a school outbreak since reopening - whether teacher, child, cleaner, chef, caretaker.

What the Belgian study shows is 90% is asymptomatic coming into school.

At-school infections are very low, even in the no-mask primary school environment.

It seems inconceivable we will see a repeat of 2009, when over 1,000 Irish kids were affected by Swine Flu in school.

The key takeaway for adults and children from this study is the risks at school are smaller than the risks outside school - but neither are zero risk.

You can minimize risk further by reducing close contacts and getting the flu vaccine to guard against flu.

Hope that helps.