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🧵

First, masks. I don’t pay attention to simulations and mannequin studies. Those of us who write COVID policies for healthcare settings started with this systematic review and meta-analysis which used data from COVID and other 🦠s.

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.

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 I mostly wore a basic surgical mask (unvax) when caring for (often unmasked) COVID+ kids, at least through winter ‘20-‘21 peak, when N95 supply improved. I do think they helped, but we should acknowledge superior ventilation of hospital rooms, especially negative-pressure rooms.

@ShiraDoronMD That’s ok. “The electrostatic charge”. @MarkChangizi they don’t get it.

@ShiraDoronMD I thought n-95s had the electrostatic charge, not surgical masks. Is that not the case? Would love some clarification