Quote

the claim that masks don’t work is demonstrably incorrect, and appears to be based on a combination of flawed assumptions, flawed meta-analysis methods, errors of reasoning, failure to understand (or refusal to acknowledge) mechanistic evidence, and limitations in critical appraisal and evidence synthesis. Masks and respirators work if and to the extent that they are well-designed (e.g., made of high-filtration materials), well-fitting and actually worn.

Interpretation Notes

It’s hard to improve on the authors’ own words on this one, but…

• Masks work.
• Better (and better-fitting) masks (respirators) work better.
• They only work when actually worn.
• “Scientific” claims to the contrary are rooted in — at best — utter incompetence.