@sirfredfredgeorge
One thing on both "teachers" and "7-8 months" etc. all of that can be heavily biased by testing (teachers more likely to test, they're a profession where regular LFD is encouraged, unlike others) and by the prevalence in the community which is mediated by lockdowns. Of course the commonest time between infection in cases found 7-8 months later as that's the time between the waves in the current situation.
It's the same with Delta - the only chance of detecting re-infection is with delta as there were so few cases found before the alpha wave (remembering no testing for 90 days so no detection in the first 3 months) and the number of original individuals detected was so low.
Same again with "living in multiple occupation" etc. correlation, just means you're more likely to be exposed to any virus so therefore more likely to be re-infected, doesn't tell us anything about the waning or variant protection.
So those things don't tell us much (doesn't mean they're not true, and doesn't mean they aren't entirely reasonable)
The better news is the "lowest amount of virus" as that suggests that alpha protection is actually still good at preventing delta infection as those individuals who didn't need to exercise much of an immune response are more likely. However that doesn't explain the relatively poorer vaccine protection (which should be a high amount of virus)
Other professions test regularly too. For example, health workers, social care workers. Our hairdressers are testing regularly, as they are doing personal care. And so on. So I wouldn't think that teachers are the only large group of workers testing.
It's interesting that high levels of infection in education workers are now considered "not news to anyone" as up till very recently this was hotly contested on here.
I'm hoping vaccination in secondary schools will make a difference.
I note that the US is now vaccinating 5-11 year olds with 1/3 dose of Pfizer (I haven't seen the research findings presumably providing the rationale for this particular dose ).
Here's a New York Times article which might be of interest (I have managed to read it without paying anything) www.nytimes.com/2021/11/02/well/kids-covid-vaccine-shot.html?campaign_id=190&emc=edit_ufn_20211103&instance_id=44532&nl=updates-from-the-newsroom®i_id=107339928&segment_id=73452&te=1&user_id=ad926f220b2fc5bec351a5631a508c1b
"To date, nearly two million children ages 5 to 11 in the United States are known to have been infected with the virus, and 8,300 have been hospitalized. A third of those hospitalized were admitted to intensive care units, and at least 170 have died. More than 120,000 children in the United States have lost a parent or caregiver to the disease."
The rates of hospitalisation are about 0.4% of known infections and The death rate looks to be a lot higher than ours, especially for the young age of the children. There are apparently about 24.3 million children aged 6-11 in the US.