Researchers in Canada randomly assigned 446 nurses to wear N95 or surgical masks during a few months of cold and flu seasons (September to December). Then they tracked how many nurses got the flu or a cold.


Both masks performed just as well at preventing the transmission of the viruses. About 9% percent of nurses wearing surgical masks got sick versus 10% wearing N95 respirators.


The Journal of the American Medical Association (Radonovich et al., 2019) randomly assigned 2,862 American nurses to wear N95 or Surgical masks. The study resulted in surgical masks accounting for less flu infection rates than N95 respirators.


Researchers in Australia studied parents taking care of their children who were sick at home with the flu. About 16% of parents not wearing a mask got sick, compared to 8% in the surgical masks and N95 respirator groups (called “P2” masks in Australia).

Thus, the surgical masks were just as effective as N95 respirators. And the effect size was fairly large—half the infection rate.


There is scientific evidence finding that masks prevent flu infection and surgical masks prevent infection of viruses like the coronavirus (Covid-19), as well as N95 respirators.

*Open Data Source: Smart Air Systems