I want to highlight what just came out: the Cochrane review on masking. It shows that community mask recommendations have no firm data to support it. The authors write:
“There is a need for large, well-designed RCTs addressing the effectiveness of many of these interventions in multiple settings and populations, as well as the impact of adherence on effectiveness, especially in those most at risk”
… Here is the big summary finding. With 276,000 participants in RCTs or cluster RCTs, masking does nothing. No reduction in influenza like or Covid like illness and no reduction in confirmed flu or COVID. That’s stone cold negative. See those effect sizes and confidence intervals.
Link to the Cochrane review: