I may be the only person here who knows the details of how the PHE sampling was done as I have two friends whose DCs were included.
Firstly, it's not finished (WILL it get finished now PHE has been dumped??)
Secondly, (I am really disappointed in The Guardian for this as it's more right wing press territory), this is important : IT's NOT FINISHED! In particular, they have hardly any data for anyone over 11
Thirdly, there were vanishingly few vulnerable children in the sampling because they, on the whole, did not return to school during the sample reopening
Lastly, the survey was conducted when class sizes were halved and social distancing was at least partially being enforced both in schools and in the community , and when shielding was still in place.
I think things coming out of Georgia (which he fleetingly mentions , almost flippantly), and Canada and various other schools in the US rather suggests that the findings may be contradicted at some point.
Even Alasdair Munro of 'Don't Forget the Bubbles' (and poster boy of Us For Them) has had ot update ghsi recent online met research to acknowledge the Georgia stuff is a concern.
Can we also note, this article is an opinion piece by a paediatrician, who have very different child health concerns to virologists. I am not sure one specialism should trump another , but I am certain the virologists have greater knowledge of the virus itself. DH's cardiologist ahs a lesser understanding of much around covid than one might expect, for example.
The idea that a child should return to school , and the vulnerable family member should isolate is laughably naive. I think it presupposes all clinically vulnerable people are pensioners. Many of them have lost the right not to work . Some of them might be the said child's actual parents!!