I can't understand why anyone would be against cleaning the air in schools: HEPA filters don't just remove virus particles from the air, they also remove pollutants and allergens. I understand that money is short, but if we don't start with protecting children's health, then there isn't much point in anything else we do for them.
My child, or yours, may be able to shrug off infections, but what about the child with weak health? The one with a sibling with cancer? Ill parents etc? In any case, their health may seem to be fine, but there are hundreds of studies all showing that Covid damages the immune system, making us more susceptible to other illnesses after we've had Covid, and also that they'll affect us worse than pre-Covid, and that multiple Covid infections increase this impact. 4.5 years is simply way too soon to say our children's health is fine with repeat Covid infections - HIV took 10 years to become AIDS in most cases. Polio can cause awful effects decades after infection. We should be using the precautionary principle and cleaning the air - France and Belgium are already doing so. We already know Covid causes serious after effects for many people, regardless of how much people want to minimise it. "MY child is fine" isn't the argument people think it is.
There is just no good reason for NOT reducing infections in schools and, because we have better information since Covid began about how to clean the air, we should DO better. I wish I'd known about HEPA filters when I was a teacher, I would definitely have had them in my classroom. Those teachers who DO have them report far fewer illnesses, of their own and among pupils.
On a more cynical note: the Houses of Parliament and major Government departments have installed HEPA filtration. If it's good enough for them, it's good enough for our children. And the World Health Organisation VERY QUIETLY installed HEPA filtration in their offices in (I think) May 2020 - while telling the rest of us that Covid spreads by droplets and to keep 2m apart from each other, while they KNEW it is Airborne.
So yeah, not a happy bunny that schools are infested with viruses and bacteria and that we know how to improve the situation, but we're not doing so. No doubt in years or decades to come, we'll wonder why cleaning the air was ever debated, it will be so obvious. The food and water we consume must reach a certain quality - why not the air we breathe.
If there's an afterlife, I imagine Semmelweis is raging.