LONG THREAD on masks. Mute if not interested.
Do masks work? Why do some people claim they don’t work? Do they cause harm? What kinds of masks should we wear? How does masking need to change now we know that Covid is airborne? When can we stop wearing them?
Get your popcorn.
1/

— Trisha Greenhalgh (@trishgreenhalgh) July 11, 2021