This picture is creating misplaced outrage bc Biden is in a surgical mask instead of an N95.

1. Yes, N95s or KF94s are better if you need to wear a mask


2. Everyone is fully vaxxed and boosted, so masks provide limited benefit (especially considering 5 and 6)
3. Even though surgical mask has lower efficiency, the combined efficiency of two 70% masks is 91%. Saying they’re useless is incorrect.
4. In addition, surgical masks get dinged bc ‘leaky’ out the sides, but this misses point that they still help lower the concentration in the cone of emissions directly in front and slow the speed of the emission jet. (particularly relevant when you factor in 5 and 6 next…)
5. This is a high-ceiling room so it has a large dilution volume.
6. The room also has good ventilation and filtration (I worked with Architect of the Capitol and others in gov’t early on in pandemic on this…)

bc or 5 and 6, emissions from the side of mask dilute quickly.
All in all, a very low risk environment, surgical mask or not. (If your argument is Biden should be wearing an N95 for ‘signaling’ reasons, just say that, but don’t pretend it’s about risk reduction in this scenario.)

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More from @j_g_allen

27 Nov
What can schools do right now, if feeling anxious and don't want to wait 2 weeks til Omicron gets sorted out? Implement the simple tips from our Lancet COVID19 Commission report:…

(BONUS...improvements to school buildings come with many other benefits!) ImageImage
Where’d the ‘2 weeks’ come from? 👇
Read 4 tweets
20 Nov
Some people have have high ACE2 expression, and some have “almost none”

For the life of me, I can’t figure out why so few have engaged with this research that’s been out as preprint from @celldeathlab for over a year…

Read 4 tweets
4 Nov
Jan 2020: rapid tests (@RanuDhillon; @sri_srikrishna)
Feb 2020: ventilation; filtration; portable air cleaners (me)
Mar 2020: airborne (@linseymarr)
Mar 2020: masks (@zeynep)

We knew what it was, how it spread, how to test, and how to stay safe before vaccines *very* early on
Feb 2020: ventilation; filtration; portable air cleaners (me)…
Read 5 tweets
22 Oct
Here are 4 things we should do to prioritize the health of children:

1⃣ Mandate vaccines for all adults in schools
2⃣ Host at-school vax clinics in every school
3⃣ Expand use of rapid antigen tests
4⃣ Improve ventilation and filtration

Details in thread…
1⃣ "Mandate vaccines for all adults in schools, as Los Angeles and New York City have done. We know this causes vaccinate rates to rise sharply. New York City’s Department of Education saw its rate spike from around 50 percent in early August to 95 percent."
2⃣ "Host at-school vaccination clinics in every school in the country. Any family that wants their child vaccinated should have that opportunity as soon as vaccines are available. No more crossing our fingers and hoping that people will find a local clinic or CVS to go to."
Read 6 tweets
22 Oct
Many masking policies rely on these two CDC metrics. They’re deeply flawed. How has this escaped scrutiny?

“CDC primarily uses two metrics: seven-day-average case numbers per 100k people and the rate of tests that come back positive. Both have problems.”…
“The first metric might seem reasonable, until one recognizes that there are vast differences in risk by vaccination status and by age. Vaccinated people are 29 times less likely to be hospitalized than the unvaccinated, and children are hospitalized at low rates, too.” 2/
“Despite this, the CDC’s metric is being uniformly applied across the country. Case numbers were once a reliable indicator of population risk, accurately foreshadowing hospitalizations and deaths, but this is changing as more of the country attains some level of immunity.” 3/
Read 8 tweets
16 Oct
This backlash was predicted. We shouldn’t extend controls beyond what’s necessary, or else we lose trust. The pushback is not coming from hoaxers or anti-maskers or anti-vaxxers - and it’s not limited to this campus. The window is closing on rational people accepting this…
Read 4 tweets

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