N95 & KN95 have repeatedly been demonstrated to work in lab experiments, physical demos & the lived experience of BSL-3 workers.
That randomized clinical trials of mask *mandates* don't always detect benefit for a given population & given virus should be taken w a grain of salt.
That randomized clinical trials of mask *mandates* don't always detect benefit for a given population & given virus should be taken w a grain of salt.
The 2018 study is here. My thanks to the authors for such a clear demonstration of an important principle of clinical research.
bmj.com
bmj.com
Loading suggestions...