Unlike other studies looking at masks, Danmask was a randomised controlled trial – the highest quality scientific evidence. It revealed a minimal statistical difference between those who wore medical masks & those who did not in terms of COVID-19 infection https://www.spectator.co.uk/article/do-masks-stop-the-spread-of-covid-19-

This was written by a Professor of Evidence-Based Medicine, Director of the Centre for Evidence-Based Medicine & Director of Studies for the Evidence-Based Health Care Programme & Centre for Evidence-Based Medicine, University of Oxford, with a senior tutor & research fellow.

Influenza like illness rates 3 times higher with cloth masks when compared to control group:
https://bmjopen.bmj.com/content/5/4/e006577
Prof. Carl Heneghan, Oxford University: "The high quality trial evidence for cloth masks suggest they increase your rate of reinfection."