Dr. Trisha Greenhalgh is well-known to those who follow the debate closely over airborne COVID-19.
In May, the professor of primary care at Oxford University was the lead author of a paper that issued a scathing denunciation of public-health officials.
It came in connection with them not acting earlier in response to growing evidence that airborne transmission of the novel coronavirus was far more likely than previously believed.
She and her fellow authors described this oversight by such influential organizations as the World Health Organization as a "mystery and a scandal".
Today, Greenhalgh was beating the drum again about airborne COVID-19, this time in a 82-tweet thread.
It focused on masks. You can read it below.