Surgical masks as good as N95 against respiratory virus

Unfortunately, it also shows that neither mask is particularly effective:

"A large study conducted in a New York hospital system after the 2009 outbreak of H1N1, or swine flu, found almost 30 percent of health care workers in emergency departments contracted the disease themselves, Dr. Perl said."

Given that mask-wearing is unlikely to be higher among the general population than among health care workers in emergency departments, it seems unlikely that it will be working any better in the general population.

Anything is better than nothing, I suppose, but add this to the Bangladesh study (that also showed rather meager improvements even for large changes in mask-wearing), and it looks increasingly like this is mostly a just-better-than-placebo.