NEJM should tell this to all the non-healthcare companies that mandate mask-wearing.
From the NEJM: "This article was published on April 1, 2020, at NEJM.org."
The article itself, reads like an op-ed as opposed to a research paper subject to peer review. Also, we have learned a lot about the Wuhan Flu over the last two months since the article was published, and what the so-called experts thought might be true two months ago, has often been wrong or misguided.