As I said, I'm a layman, but several things jump out to me. The first thing I think of is that the meta-study you linked is for influenza. Obviously covid and

As I said, I'm a layman, but several things jump out to me. The first thing I think of is that the meta-study you linked is for influenza. Obviously covid and influenza are similar but I think there are important differences (we did not, for instance, have as many cases of influenza in any of the last fifty years as we have of covid this year). In particular, I know that the asymptomatic transmission of covid is unusual and is not something that happens in influenza[0]. The studies that support mask wearing in my link are on mask mandates (though there are also case studies that suggest masks have been effective). I believe that mandating masks reduces transmission of the virus and I don't think it's necessary to reconcile that fact with the fact that masks don't reduce the spread of influenza. The version of the study you linked is formatted oddly and the tables are on another page. A pdf of their article is easier to read, I think [3]. From Table 2 (and the discussion around it) I take that they are hoping to catalog open questions and are not seeking to make a recommendation about proper procedure. Therefore I think it's perfectly in keeping with Jingyi Xiao, et. al. to recommend wearing masks based on the covid-specific studies while recognizing we have no evidence that masks prevent influenza. [0] While you can transmit influenza when you're not showing symptoms, my understanding is that covid is different enough that we shouldn't compare them. That could be wrong and if you have anything to contribute I'd be interested to see it. [1] https://www.healthaffairs.org/doi/10.1377/hlthaff.2020.00818 https://www.healthaffairs.org/doi/10.1377/hlthaff.2020.00818 [2] https://www.researchgate.net/publication/342198360_Association_of_country-wide_coronavirus_mortality_with_demographics_testing_lockdowns_and_public_wearing_of_masks_Update_June_15_2020 https://www.researchgate.net/publication/342198360_Associati...