My link is from the Oxford Center for Evidence-based Medicine. Yours is a propaganda website made by a guy who teaches online ML classes. Jeremy Howard has no b

My link is from the Oxford Center for Evidence-based Medicine. Yours is a propaganda website made by a guy who teaches online ML classes. Jeremy Howard has no background in science or medicine, and his website consistently mischaracterizes the same data presented by CEBM. If you have to believe two different interpretations of the same data, prudence indicates that you should choose the interpretation coming from an expert. That said: 1) the study in question had a control arm of voluntary compliance with surgical masks. These are neither “medical grade”, nor was the compliance rate verified. 2) Regardless, it doesn’t matter: cloth masks were significantly more harmful than the control. 3) I agree that we should be careful to discriminate between studies of respirators, masks, “face coverings”, PPE and source control. So you should take the time to actually read the studies that Jeremy Howard cites. You’ll find that nearly all of the studies on masks are for respirators in medical settings, and that (as the CEBM link confirms, if you bothered to read it), the few studies of mask use by the general public have had ambiguous or negative outcomes. It isn’t even close: if you omit the studies conducted in medical settings, there’s almost no evidence for masks at all. 4) The CDC link isn’t a scientific article, it’s a review. Moreover the authors are clear that they are not contradicting their previous findings: ” To our knowledge, only 1 randomized controlled trial (4) has been conducted to examine the efficacy of cloth masks in healthcare settings, and the results do not favor use of cloth masks.” The authors are explicit that cloth masks are unsupported, possibly harmful, and only to be used as a last resort. You really should read the links you cite before you make strong claims about what they say.