This is an in vitro study. In vivo, there's a self-selection bias for non-occupational N95 use that would tilt observed difference in protection rates between N95 and surgical mask wearers.<p>Original study [0]<p>MPG press release [1]<p>[0] <a href="https://www.pnas.org/content/pnas/118/49/e2110117118.full.pdf" rel="nofollow">https://www.pnas.org/content/pnas/118/49/e2110117118.full.pd...</a><p>[1] <a href="https://www.mpg.de/17916867/coronavirus-masks-risk-protection" rel="nofollow">https://www.mpg.de/17916867/coronavirus-masks-risk-protectio...</a>
Most people already early convinced themselves by pure logic that masks should have an impact, still today you see this opposed here&there.<p>Looks like a well carried out study and another data point, many influencing factors considered, data available.<p>Full tweet: The case for masking up: new study shows tight-fitting #FFP2 & vKN95 face masks drastically reduce the risk of #COVID19 infection - but even ill-fitting masks still significantly reduce the risk of infection <a href="https://bit.ly/31m9JKE" rel="nofollow">https://bit.ly/31m9JKE</a> @maxplanckpress<p>Their summary: <a href="https://www.mpg.de/17916867/coronavirus-masks-risk-protection" rel="nofollow">https://www.mpg.de/17916867/coronavirus-masks-risk-protectio...</a> "Well-fitting FFP2 masks reduce the risk at least into the per thousand range."<p>Full paper: "An upper bound on one-to-one exposure to infectious human respiratory particles" <a href="https://www.pnas.org/content/118/49/e2110117118" rel="nofollow">https://www.pnas.org/content/118/49/e2110117118</a>