Why I believe it is simultaneously true that masks work and mask mandates do not work. The reasons form the basis for our ability to move forward together. A long🧵

N95s were in disgustingly short supply that first spring. Many hospitals reserved them for COVID patients undergoing high risk procedures only. We wore surgical 😷 for the rest. And we found something amazing: HCWs weren’t higher risk than other essential workers.

Despite prolonged close contact (we practically bathe in 🦠 all day), seroprevalence rates among HCWs were consistent with the surrounding community, and patient facing HCW were not at greater risk than non patient facing. @ericashenoy summarized it in these slides in 2020.

Little known fact: the patients, for the most part, are not wearing masks. One-way masking is how we have always used them. On the sick person or the HCW, not both. Oh, and if you’re worried the holes are too big? That’s ok. The electrostatic charge is part of the mechanism.

So if masks work, why don’t mask mandates? Because: a. Most spread happens in places you wouldn’t wear a mask (at home, at social gatherings with friends etc, not at the grocery) b. People are wearing cloth masks (which don’t work)

c. People aren’t wearing them right d. It’s not realistic to expect that people keep a mask on all the time, because they need to eat and drink (traveled by air before the mandate lifted? people are eating and drinking every second in airport and plane)

That’s not to say that we need to tighten the mandate & require continuous wearing of N95s. Countries/cities/schools with mandates haven’t had different shaped curves than those without, even if they required N95s. Plus if you mandate medical grade PPE, you’d better provide it.

What does this mean? It means mandates are not effective or necessary, even when cases are rising. They cause rifts in society for no reason. If you’re high-risk or risk averse, a medical grade mask will protect you as well as it would if others were wearing it too.

@JenniferNuzzo in this @landmanspeaking interview hit the nail on the head. There are more important things we should do to protect the public, like vaccinations and testing to treat.

Getting COVID is inevitable, so I’m not willing to hide my face forever. Let’s get back to a place of mutual respect. Of evidence-based science rather than ideology. *That* is how we take care of each other.

@ShiraDoronMD 1/Please stop misinforming people. You do not have experience, education, or expertise in efficacy of masks. Everything you've posted is from the biased, uninformed viewpoint of someone ignorant of basic physics, fluid dynamics, and engineering. I doubt you know much about

@ShiraDoronMD Lol..this WHO funded meta-analysis was when WHO wrongly publicly claimed that this chimera wasn't transmitted via aerosolized airborne virions. So this whole meta-analysis is based on the false premise that the main means of transmission is larger sprayed droplets..which it isn't

@ShiraDoronMD You missed one. "surgical masks... There is limited evidence for their effectiveness in preventing influenza virus transmission either when worn by the infected person for source control or when worn by uninfected persons to reduce exposure" - CDC, May/20