Masks have no clear effect on the transmission of respiratory viruses. That's the conclusion of a major review of 78 RCTs led by Dr. Tom Jefferson. Oxford's Dr. Carl Heneghan interviews him about these striking findings.

https://dailysceptic.org/2023/02/06/dr-carl-heneghan-interviews-dr-tom-jefferson-about-his-major-new-study-showing-masks-have-no-clear-effect/