"In the end, there was no statistically significant difference between
those who wore masks and those who did not when it came to being
infected by Covid-19. 1.8 per cent of those wearing masks caught Covid,
compared to 2.1 per cent of the control group. As a result, it seems
that any effect masks have on preventing the spread of the disease in
the community is small."
https://www.spectator.co.uk/article/do-masks-stop-the-spread-of-covid-19-