Thread by @DrEricDing

💡UPGRADE TO PREMIUM MASKS—"We need to talk about #BetterMasking. We need to talk #N95 Respirators—would do a lot for both people who are not yet vaccinated & protect others who might become infected." ➡️ WE NEED KN95/N95/ELASTOMERIC for #DeltaVariant.🧵

2) 7 months ago, I called on everyone to switch to premium masks when the #B117 #AlphaVariant was surging. Since then FFP2 and KN95 masks have become super cheap and common. Even N95 respirator has now become more common as well. And Elastomeric respirators are more common too.

https://twitter.com/DrEricDing/status/1353186978519539712

3) Lots of studies show that the respirator-grade premium masks are what we truly need. The leaky partial protection of cloth and flimsy unfitted surgical alone just not enough.

https://twitter.com/DrEricDing/status/1353191441040863233

4) DOUBLE MASK of surgical + cloth is a poor man’s close enough solution that @CDCgov recommended officially in February (because they know cloth isn’t enough). The issue is that CDC has basically forgotten to enforce & remind people about double masking. Sloppy messaging lately.

https://twitter.com/DrEricDing/status/1359536244464766980

5) While surgical mask material is theoretically good barrier, the problem is their fit. There is well known gaps on the sides with surgical masks that even CDC admits are problematic. Hence CDC recommends a special tied surgical mask—see photo in panel C below. But it’s not easy

https://twitter.com/drericding/status/1359539175628898305

6) here is now to KNOT and FOLD a surgical mask to ensure tight fit to reduce side gaps. Fit is critical!

7) that said, CDC’s own data suggests that this fitted surgical mask hack isn’t the best - better than no mask for sure- but it’s not as good as double mask when only one person of pair masks. It is equal to double mask if BOTH people equally mask.

https://twitter.com/drericding/status/1359540044739059716

8) the sad thing is that I haven’t heard @CDCDirector or @CDCgov talk about double masking or even the surgical fitted trick for half a year now. It’s been mostly forgotten. And especially when many don’t wear any mask anymore, expecting everyone to mask for protection is risky

https://twitter.com/drericding/status/1359541827456622594

9) so if only one person wears a mask, should it be SOURCE (sprayer of aerosols) or RECEIVER (inhaler of aerosols)? If only 1 person masks, source masking better—a single unknotted surgical mask is almost no use if only the receiver masks. But if many don’t mask—PREMIUM MASKS!

https://twitter.com/drericding/status/1359549413652389890