FFP2-Masken in der Schule: Infektionen werden verschoben, nicht verhindert

Effects of wearing FFP2 masks on SARS-CoV-2 infection rates in classrooms | medRxiv

medRxiv - The Preprint Server for Health Sciences

https://www.medrxiv.org/content/10.1101/2022.07.24.22277968v1