Do Masks Work? Yes. No. Maybe.

‘Whether or not masks “work” is a multilayered question — one involving a mix of physics, infectious disease biology, and human behavior. Many scientists and physicians say the Cochrane review’s findings were, in a strict sense, correct: High-quality studies known as randomized controlled trials, or RCTs, don’t typically show much benefit for mask wearers.

But whether that means masks don’t work is a tougher question — one that has revealed sharp divisions among public health researchers….’

— via Undark