Masks: A Twitter thread by Trisha Greenhalgh (Professor of Primary Care Health Sciences)

Summary

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?

In this long-read Twitter thread Trisha Greenhalgh, Professor of Primary Care Health Sciences at the University of Oxford, outlines the data.