Thanks for your comment- I’m pleased some people take an interest in research trials, but it genuinely is a legit study, the original linked article is from Science Direct if you open the link, but you will need an Athens password to access it so I have also included some other reprint versions in another comment if you are interested in COVID mechanisms specifically.
My purpose was to encourage people to look at alternative technologies like HEPA filters to help everyone access shared spaces safely - and not need to rely on masks. And to debunk the idea that infection improves immunity or immune health- it doesn’t.
HEPA filters demonstrate really good performance in schools for reducing illness and absence and improving teacher retention… ie a more normal life.
Here is an extract from the Class-ACT study chapter 9 ( you can find the full report online) showing how HEPA helps in spaces with shared air.