A huge number of scientific sources tell about the dangers of several covid infections. The discussion becomes heavy if every sentence has to be justified with a source that most people don't even read. However, here are a few I glanced at this morning. This applies especially to school children who spend their days in a crowded, poorly ventilated space.
https://impact.economist.com/perspectives/health/incomplete-picture-understanding-burden-long-covid
(direct link to the report: https://impact.economist.com/perspectives/sites/default/files/download/ei264_-_an_incomplete_picture_understanding_the_burden_of_long_covid_v8.pdf)
https://www.modernatx.com/media-center/all-media/blogs/long-covid-awareness-day-2024
https://www.imperial.nhs.uk/about-us/news/covid-may-have-small-but-lasting-effects-on-cognition-and-memory
https://www.statista.com/statistics/1388245/uk-sick-leave-figures/
https://libguides.mskcc.org/CovidImpacts/Immune