NEW: There's an emerging argument that masks don't actually work. It's based on a recent study published by the CDC, which reportedly showed that 85% of mask-wearers contract #COVID19. This is a dangerous mischaracterization of the study. Here's what the work really showed: https://twitter.com/NickKristof/status/1316893848958881792

CDC looked at 154 adults with symptomatic #COVID19 and compared them to an uninfected control group. Of the patients with #coronavirus, 70.6% reported ALWAYS wearing a mask and 14.4% OFTEN did. From a distance, it looks like 85% of mask-wearers got COVID. https://www.cdc.gov/mmwr/volumes/69/wr/mm6936a5.htm

But you've got to read the actual study. Here's the key detail: COVID patients were twice as likely to have dined at a restaurant. Why does this matter? Because people take off masks to eat. You might report that you ALWAYS wear a mask but we know it comes off when you're eating.

The takeaway from this study: Restaurants appear to be an important risk factor for #coronavirus transmission. As we reopen society, researchers are trying to find ways to make dining more safe, but they are not questioning the use of masks. You shouldn't either.