“Masks block some fraction of viral particles from dispersing from those who are infected and from infecting those who are susceptible . . . studies that did not find masks to be effective had limited statistical power and therefore do not imply that masks are ineffective . . . The studies that did not find statistically significant effects prove only that masks cannot offer protection if they are not worn.”

Andrew Klaassen writes: I recently saw this metastudy on the effectiveness of masks being shared around. I haven’t found a discussion of it on your blog, so if you haven’t already I was wondering if you’d be willing to comment … Continue reading → …