Share this page!

Enter URL or ID to Unroll

You can paste full URL like: https://x.com/threadreaderapp/status/1644127596119195649
or just the ID like: 1644127596119195649

How to get URL link on X (Twitter) App

  1. On the Twitter thread, click on or icon on the bottom
  2. Click again on or Share Via icon
  3. Click on Copy Link to Tweet
  4. Paste it above and click "Unroll Thread"!
  5. More info at Twitter Help
Mike Hoerger, PhD MSCR MBA Profile picture
@michael_hoerger
Jul 14, 2022 • 10 tweets • 10 min read • Read on X
Kids <2 yrs old can’t mask.
Kids <6 months can’t vax.

Many parents are using strollers w/rain covers to try to get some protection during essential activities.

Does adding a #PAPR or #HEPA device help?

I tried 6 models: engrxiv.org/preprint/view/…

#PAPRbuggy #HEPAbuggy
1/10 Image
First off, thanks @RealSexyCyborg for the original design. Thanks to @ccwake1, @gjmf, @drgregkelly for ideas too. Happy to acknowledge!

My goal was to test 6 models & help relate them to non-engineers.

2/10

The PAPR & HEPA buggies I tested had an estimated 57-951 air changes per hour (ACH) in these TINY spaces. The worst design had about 3x the air cleaning of an OR.

You can make a #PAPRbuggy that’s super discrete for about $110 more than an existing stroller & rain cover.

3/10 Image
With even a cheapo ($55) HEPA, you can make a relatively discrete #HEPAbuggy w/good air cleaning (see Figure A1.5 in preprint).

BUT, I also tested some power models. This one runs at an estimated 900+ ACH, or about 60x the minimum rate of an OR. 😎 Vroom vroom.

4/10
Want to learn more about a #PAPRbuggy or #HEPAbuggy?

See the preprint:
🔸 Figure A1: Design ideas
🔸 Tables 1 & A4: Estimated specs
🔸 Table A3: Parts & supplies w/links
🔸 Tables A1-A2: Help w/any calculations

engrxiv.org/preprint/view/…

5/10 Image
If you are a COVID-cautious parent, be forearmed that trolls will troll.

Sticks & stones. I knight you a #PublicHealth ambassador. Stand tall. Your work is needed.

Check out Table A5 for what to expect (final page).
engrxiv.org/preprint/view/…

6/10
If you’re a #COVID-cautious #parent, I also hope you’ll read the 1st paragraph of this paper (pg. 3).

✅ You’re doing the right thing
✅ You’re smart
✅ Feel validated
✅ Reference #7 is absolutely damning
✅ Kids deserve a better world

engrxiv.org/preprint/view/…

7/10
H/t 🎩to @sri_srikrishna for the #CorsiRosenthalBox article that inspired my write up.
sciencedirect.com/science/articl…

Thanks also to @JimRosenthal4, @CorsIAQ, @joeyfox85, and others for teaching about air cleaning

8/10
I posted Naomi’s original design, but also check out Greg’s "Pram-PAPR." He’s got a different air filter & older child.

Mine are baby twins, so I’ve got some different models in the paper & will test out more double strollers down the line too.

9/10
Thank you for your advocacy - @MamaWeasleyy, @PTF_org, @Annalisa840917, @mir_ocall, @maskupmama, #ImmunizeUnder5s #covidkids

Please share the #PAPRbuggy & #HEPAbuggy with families of young children!

If I have to 🔒 my account, send the link:
engrxiv.org/preprint/view/…

10/10

• • •

Missing some Tweet in this thread? You can try to force a refresh
　

Keep Current with Mike Hoerger, PhD MSCR MBA

Mike Hoerger, PhD MSCR MBA Profile picture

Stay in touch and get notified when new unrolls are available from this author!

Read all threads

This Thread may be Removed Anytime!

PDF

Twitter may remove this content at anytime! Save it as PDF for later use!

Try unrolling a thread yourself!

how to unroll video
  1. Follow @ThreadReaderApp to mention us!

  2. From a Twitter thread mention us with a keyword "unroll"
@threadreaderapp unroll

Practice here first or read more on our help page!

More from @michael_hoerger

Mike Hoerger, PhD MSCR MBA Profile picture
Jun 3
1/ PMC COVlD Dashboard, June 2, 2025 (U.S.)

National COVlD transmission recently fell to its lowest levels since the pre-Delta era.

It's go-time for many who have delayed medical appointments. The situation will likely get much worse in Jul/Aug.
2/ PMC COVlD Dashboard, June 2, 2025 (U.S.)

An estimated 1 in 211 are actively infectious. Most states are "low" or "very low" per CDC.

The situation remains serious even in a relative "lull." >1.5 million weekly estimated infections to result in 600-900 excess deaths.C19 heat map
year over year graph, tracking closely with the median and past 2 years
Current Levels for Jun 2, 2025 % of the Population Infectious 0.5% (1 in 211) New Daily Infections 227000 New Weekly Infections 1589000 Resulting Weekly Long COVID Cases 79,000 to 318,000 Resulting Weekly Excess Deaths 600 to 900 Monthly Forecast Average % of the Population Infectious 0.7% (1 in 139) Average New Daily Infections 344566.6667 New Infections During the Next Month 10337000 Resulting Monthly Long COVID Cases 517,000 to 2,067,000 Resulting Monthly Excess Deaths 3,700 to 6,200 Running Totals Infections Nationwide in 2025 70132000 Average Number of Infe...
Graph of the whole pandemic, 11th wave forthcoming
3/ PMC COVlD Dashboard, June 2, 2025 (U.S.)

By the end of the month, we forecast an increase to 450k daily infections. If NB.1.8.1 takes off, closer to 600k. If overhyped, percolating only slightly higher.Past 12 months and forecast
Read 5 tweets
Mike Hoerger, PhD MSCR MBA Profile picture
May 26
1) PMC Dashboard, May 26, 2025 (U.S.)

The lull exit is coming. Despite being in a lull:

🔥1 in 180 actively infectious
🔥1.9 million weekly infections
🔥>93,000 new #LongCOVID cases from the week's infections
🔥1,100 excess deaths from the week's infections

This is a "lull."
2) PMC Dashboard, May 26, 2025 (U.S.)

The forecast calls for a near-doubling in transmission the next month to 450k daily infections.

The 95% confidence interval includes flat transmission (percolating), or escalating to 650k (if NB.1.8.1 takes off). Forecasting graph, summarized in post
3) PMC Dashboard, May 26, 2025 (U.S.)

Looking at year-over-year transmission, 2025 (red) is closely tracking the median (gray).

It transmission accelerates, it could look more like last year (orange). If it slows, more like two years ago (yellow). Year-over-year graph summarized in post
Read 7 tweets
Mike Hoerger, PhD MSCR MBA Profile picture
May 25
1) CDC & Biobot wastewater surveillance both show the West region in an apparent uptick in C19 transmission.

Here's the graph of regional transmission from CDC data with the West in green: Estimated Percentage Actively Infectious* PMC Model Raw CDC Data National 0.6% (1 in 180) 0.5% (1 in 196) Northeast 0.4% (1 in 236) 0.4% (1 in 257) Midwest 0.5% (1 in 209) 0.4% (1 in 227) South 0.6% (1 in 160) 0.6% (1 in 175) West 0.8% (1 in 129) 0.7% (1 in 140)
2) This image zooms in on the West (green line) so you can see the apparent departure from the C19 lull more easily. Zoomed in graph from prior post. More stats in the ALT text there.
3) Biobot still provides national & regional C19 updates. They usually post sometime between Thursday morning & Saturday evening. IMO, their most recent data point can be viewed as the Wednesday of the prior week.

Like the CDC, they have an apparent uptick in the West (green). Biobot graph. What's striking is that the peak (for any region) is almost identical the past 3 waves, though the West apparently runs cooler on average. The West is presently highest and increasing, whereas the other regions are lower and still trending down at the time of these data.
Read 6 tweets
Mike Hoerger, PhD MSCR MBA Profile picture
May 20
PMC COVlD Report, May 19, 2025 (U.S.)

In this national "lull" in transmission, we are seeing...
🔥A quarter-million daily infections
🔥90-360k Long COVlD cases from the week's infections
🔥600-1,100 deaths from the week's infections
🔥LA, SD, NE, & GU in high transmission10 waves of C19
Heat map, summarized in post
Current Levels for May 19, 2025 % of the Population Infectious 0.5% (1 in 185) New Daily Infections 259000 New Weekly Infections 1813000 Resulting Weekly Long COVID Cases 91,000 to 363,000 Resulting Weekly Excess Deaths 600 to 1,100 Monthly Forecast Average % of the Population Infectious 0.8% (1 in 129) Average New Daily Infections 371566.6667 New Infections During the Next Month 11147000 Resulting Monthly Long COVID Cases 557,000 to 2,229,000 Resulting Monthly Excess Deaths 4,000 to 6,600 Running Totals Infections Nationwide in 2025 66986000 Average Number of I...
Year-over-year graph, currently closely tracking the median, Y4, and Y5
Full report: pmc19.com/data
PMC COVlD updates are also posted periodically on Plip Plop:

tiktok.com/@michael_hoerg…
Read 6 tweets
Mike Hoerger, PhD MSCR MBA Profile picture
May 15
1) Good luck getting any new federal research to support #LongCOVID until "covid" is dropped from the dirty words that get grant applications triaged to the trash bin.

You know which senator to call.

I just did, and got a staffer instead of voicemail.Lengthy list of words that get federal grants triaged to the trash bin, unfunded after favorable review, or defunded if already in progress. Includes "Covid-19," and no, it's not a matter of simply restating as "SARS2" or "The Rona." It might make it one step further in the review process, but this gets checked closed, and it will get canned. Hundreds of hours of work, flushed down the toilet. And that's the point.
2) I told the staffer that #LongCOVID is affecting millions and that no research will be funded to address this while "covid" remains on the banned word list.

I asked if they wanted to hear more. He did...

Here's the word list, btw
pen.org/banned-words-l…
3) I told them about my family member who was a strong Special Forces veteran, got covid once, & according to their neurologist, it triggered #LongCOVID in the form of Dementia w/Lewy Bodies.

DLB is one of the worst conditions imaginable. After a 2yr battle, they died in 2024.
Read 5 tweets
Mike Hoerger, PhD MSCR MBA Profile picture
May 3
30 million excess deaths attributable to COVID is a tremendous underestimate because most analyses insufficiently account for mortality displacement.

In the U.S., it's about 50% worse than people realize.
Mortality displacement or "harvesting" is the idea that so many people died of COVID in the early pandemic that we should actually expect to see *fewer* deaths today if COVID were "over."
In fact, we see similar or slightly higher mortality relative to pre-pandemic levels. Despite the millions of people that have died, the mortality faucet keeps running strong. It should have slowed.
Read 9 tweets

Did Thread Reader help you today?

Support us! We are indie developers!

This site is made by just two indie developers on a laptop doing marketing, support and development! Read more about the story.

Become a Premium Member ($3/month or $30/year) and get exclusive features!

Become Premium

Don't want to be a Premium member but still want to support us?

Make a small donation by buying us coffee ($5) or help with server cost ($10)

Donate via Paypal

Or Donate anonymously using crypto!

Ethereum

0xfe58350B80634f60Fa6Dc149a72b4DFbc17D341E copy

Bitcoin

3ATGMxNzCUFzxpMCHL5sWSt4DVtS8UqXpi copy

Thank you for your support!

Follow Us!

Send Email!

:(