⁣Dr Andrew Kaufman do an analysis of the first high quality study done on masks in regards to "COVID-19"

Study: "Effectiveness of Adding a Mask Recommendation to Other Public
Health Measures to Prevent SARS-CoV-2 Infection in Danish Mask Wearers :
A Randomized Controlled Trial"
https://www.acpjournals.org/doi/10.7326/M20-6817

Dr Andrew Kaufman's website: https://andrewkaufmanmd.com