2/☝️This shows about a 1% transmission rate while all kids were wearing masks in this study.
The caveat (in the earlier data we reviewed) was surveillance testing wasn’t utilized to catch many asymptomatic kids. In places where testing was used, like Omaha, they found 6x cases.
3/ Other studies found COVID-19 infected many more kids than known. Serology in MS found >10x COVID-19 cases in kids as known. (Many MS kids getting reinfected; devastating outcomes.)

INOVA/GMU study: HUGE undercount here.
Any known exposure = kid ~3x more likely infected Image
4/ Many of the cases weren’t severe, and flew under the radar. But COVID’s new, 2.4x more infectious virus is much more scary, because so many more will be infected; we get more of worst outcomes, and hospitals can easily be overwhelmed.

The personal stories are just shattering. Image
5/ Which brings us back to masking. No, you can’t say masks will prevent 99% of COVID-19 spread between kids, especially with new variants. But there’s an enormous amount of data that indicates #masks are one of the BEST measures we have to return kids to school w/reduced risk.
6/ Another CDC featured study found — while comparing schools with and without mitigations in same area and adjusting for community rates — that #mask wearing in schools reduced the risks of transmission of COVID-19 by 21%, and cases were reduced by more than a third. Image
7/ #Ventilation (as easy as open window)+ filtration (HEPA filters to remove 80-90% of particles in room air quickly) can do more to reduce cases than masks as worn by kids with the old varieties of COVID-19. (39% risk reduction versus 21% for masks).

8/ But — hey — what if we COMBINED two of the most highly effective strategies that reduce infection risks since #COVIDIsAirborne. #Masks + #Ventilation could reduce risks by as much as 90% (more in other models).

(Our note: lunch needs to be outside!)

9/ Also, just putting any machine — like a tiny ionization device in a room — isn’t likely to provide the risk reduction you’d want.

You need masks plus actual True HEPA filters, without gimmicks like “electrostatic,“ etc.

You can even make your own 👇
10/ Fact-based targets are available to help you make an effective plan.

You’ll have to do math, but 700+ engineers endorsed WHO guidelines for ventilation, which specify a MINIMUM of 10 L/s/person of CLEAN air in a classroom for risk reduction.

11/ Our schools are designed for HALF this 10 L/s/p target at 25 people/room as “basis of design.” A large number of classrooms did not meet 5 L/s/p code before APS began working the problem (where they started 👇).
Overcrowd rooms = even less fresh air per student/teacher Image
11/ Shooting for 10 L/s/person crudely translates to goal of least 5, if not 6 air cleanings of filtered air in class every hour. (More air needed for more people!)
You can check “CADR” on your HEPA (or use TWO MACHINES) and do some math 👇 + #MaskUp!

12/ A study using a real world classroom came to a similar target. They used #HEPA air cleaners that got to nearly 6 air changes of filtered air, just from the HEPAs, rapidly removing anything from the air in the classrooms they studied. Risk reduced!

13/ Another recent study noted that increasing ventilation, where we have larger numbers of unvaccinated people, could be a useful tool to stop transmission of SARS-Co-V-2. Their classroom target to reduce risks was 7 air changes/hour, or 17 L/s/person.

14/ So #MaskUp, but don’t forget that #ventilation and #filtration are just as important (if not more so) because they actually remove the stuff that’s in the air which can float for hours.

A layered🧀 approach is best with such a dangerous disease.


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More from @smartrestartaps

13 Aug
1/ A lot of the #school contact #tracing and #quarantine policies, recommended by the @CDCgov for #COVID19, and adopted by @APSVirginia, just don't make sense to regular people.

Isn't this how we'd hope to handle these situations at work? 👇
2/ Worker 😨, calling boss: Hey, I sat next to someone w/ COVID-19 for 7 hours yesterday, but am vaccinated; can I come into work and wear a mask? Have lunch in the cafeteria?

BOSS: No, work from home. Some vaccinated people have spread COVID-19. Get tested. Then come back.
3/ Worker 😨, calling boss: Has anyone in my work group had COVID-19 recently? I'm off to see my immunocompromised elderly mom, wanted to know.

BOSS: Sure, I'll check, but didn't you get that notice we sent, about case in building? Ought to get a test, in case you crossed paths.
Read 9 tweets
11 Aug
1/ Thought-provoking 🧵 on how Delta variant may be more dependent on larger clusters of infection (super-spreading!) to surge. The “k” factor or variability could be more. But add a “super emitter” to a low air flow room and 💥, then multiply by how often this is happening…
2/ The obvious applicability is one would reduce the following:
📌Eliminate situations like indoor eating at schools, in community cafeterias, and improve airflow in rooms that are ideal for superspreading. (<1 ACH for sure; close to 2 ACH should be next priority, and so on).
3/ We would also:
📌Try to screen out next super emitter from turning infectious… We’d test kids in classrooms with known case, for instance, and not just assume “had a mask on so can’t have gotten it.” Many private schools have such required pooled testing or rapid testing.
Read 6 tweets
10 Aug
Who's #unvaccinated in #Arlington?

13,540 babies/preK <4yoa (100%)
20,181 kids (ALL <12 +teens to 19) (38%)
8,957 young adults, age 20-24 (56%)
25,156 age 25-34 (46%)
12,605 age 35-44 (33%)
15,892 age 45-64 (30%)
4,519 age 65-84 (20%)
1,115 of 85+ (35%)

TOTAL: 100,051 unvaxed
There isn't a record of some of the federally distributed shots, so our amount of vaccinated could be greater for some of the adults. Maybe 5% more? 10%?

90,000 unvaccinated is still plenty for a virus to attack.

Unlike our neighbors in DC and Maryland, we have no indoor mask mandate. We are fully open. The bars and restaurants are full. With indoor gatherings and back to school full-time, there is a lot of human fuel for #DeltaVariant to burn through and spread rapidly in our community.
Read 5 tweets
30 Jul
Uh oh… APS Policy: Don’t notify kids/staff if they were near a COVID-19 case, if were wearing a mask? Hmmm…Confusing. An upset parent just sent us this APS note about contact tracing and asked us if we understood it. APS cites CDC…
BUT a 3-minute search of CDC turns up a guide for what to do if you have COVID, which CLEARLY states people you were near while wearing masks ARE CLOSE CONTACTS and must be notified. Is it any wonder why parents are worried ‘bout back to school… especially for unvaxed kids < 12?
WHY would we not err on side of at least notification? If nothing else? How many APS families include multigenerational members, caregivers for elderly, pregnant moms, new babies, or immune-compromised members at more risk from COVID-19?

Communication = caring
Read 9 tweets
30 Jul
One slide states there’s a higher risk among older age groups for hospitalization/death relative to younger people, regardless of vaccination status. Another estimates 35,000 (👀) symptomatic infections per week among 162-million vaccinated Americans.
Why is anyone saying breakthroughs are rare if CDC is estimating 35,000 symptomatic infections in vaxed people a WEEK?! with new variant??? How many — if asymptomatic infections were included? As contagious as chickenpox? More contagious than ebola?
Safety focus MUST be on AIR!
From the article: “We’ve done a great job of telling the public these are miracle vaccines,” Seeger said. “We have probably fallen a little into the trap of over-reassurance, which is one of the challenges of any crisis communication circumstance.”
Read 8 tweets

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