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JWeiland Profile picture
JWeiland
@JPWeiland
Scientist. Infectious disease modeler. Tweets and spelling mistakes are my own Models and analysis seen on @Newsweek @Fortunemagazine @FaceTheNation @TIME
15 subscribers
Oct 19 • 4 tweets • 2 min read
FYI:
All of the news stories of the sudden jump in severity of XEC comes from a dentist in the UK (Dr. Snieguole Geige) who most likely does not even know that it's only been 1/6 infections over the past month.

It's nearly impossible to judge any severity change this early. Image
Image This is not a knock for dentist speaking about covid. This is not my day job either. Sci/docs have made important contributions studying this virus even though it's outside their field. The issue:
🔸️Big claim
🔸️No data in hand
🔸️No evidence this Dr studies covid
Sep 30 • 4 tweets • 1 min read
Outlook for Fall and Winter:

This is not an official forecast, rather a general idea of how I anticipate fall and winter Covid trends to look at the moment, with XEC being the main growing variant.
⚠️A strong new variant would change this relatively positive outlook. Image The winter wave would be lead by the Northeast followed by the Midwest in terms of prevalence.

Note: I've been sitting on this outlook for 3 weeks, but waited to post it until we could see if XEC had stronger competition. That hasn't happened yet.
Aug 9 • 5 tweets • 2 min read
August 9th update:

Estimated daily infections reach 1 million. Remarkable infection rates for a summer surge. Only BA.2->BA.5 was higher in the 2022 summer.

🔸1,000,000 new infections/day
🔸1 in every 33 people currently infected
🔸74% higher than 12 month avg. Image Prevalence by region:

Every region increasing in wastewater levels. Both the South and West are at roughly 12 month highs.

Midwest: 1 in 42 ⬆️
South: 1 in 25 ⬆️
Northest: 1 in 58 ⬆️
West: 1 in 22 ⬆️ Image
Jul 19 • 4 tweets • 1 min read
July 19th update:

Another substantial increase this week (+26%). Wastewater signal now higher than last summer's peak, and over a month earlier.

🔸780,000 new infections/day
🔸1 in every 43 people currently infected
🔸45% higher than 12 month avg. Image Ratio of people currently infected by region:

Midwest: 1 in 59 ⬆️
South: 1 in 34 ⬆️
Northest: 1 in 73 ⬆️
West: 1 in 25 ⬆️ Image
Jul 5 • 4 tweets • 1 min read
Largest spike AA evolutionary jumps from 2020-2024, plotted:

BA.1 Omiron's top spot was followed closely by JN.1 Pirola, and both stand well above the rest over the past 4 years. Image Viewed from a different lens of total AA spike divergence from the current lineages, JN.1 takes the top spot. This is branch to branch distance. Also note BA.2 divergence from BA.1. Image
May 16 • 4 tweets • 1 min read
The cost of preventing a pandemic is far lower than the cost of dealing with a pandemic. The current response to H5N1 in bovine needs to be dramatically increased.
1) Federal funds for compensation of lost profits on H5N1 farms (increases cooperation)
2) Abundant sequencing of.. Image H5N1 positive cows and mammals on or near outbreak farms
3) Ramp up testing of farms and farm animals
4) Detailed sequencing metadata: date, location, etc.
5) Guarantee privacy on any humans with symptoms, test, trace, isolate, seq any positives
6) Guarantee immunity for...
May 8 • 4 tweets • 2 min read
What is "FLiRT"?

FLiRT is the clever nickname for two mutations on the spike protein of the highly mutated variant "Pirola", that accounts for >99% of all Covid right now.
F->L at position 456 and R->T at 346.
Both escape mutations were present last year, but never on Pirola. Image The two mutations are like makeup and lipstick to disguise the virus a bit more to sneak past some of your antibodies from prior infection and vaccination. And she wears it well.
Feb 1 • 7 tweets • 3 min read
A set of 8 highly mutated variant designated BA.2.87.1 were released from South Africa today from Sept-Nov 2023.

While this deserves close watch, at this point, I don't think it's as concerning as the arrival of Pirola. I'll explain my reasoning:

1/
Image It's apparently been 4 months since the first sample collection date, and it still hasnt been detected in any other country that does sequencing.

When Pirola first appeared, there were sequences spotted all over the world within a week or two of first detection.

2/
Jan 24 • 4 tweets • 2 min read
Biobot update 1/23/2024:

Wastewater receding quickly off of the peak, though still near 1 million new infections a day in America. Decline will continue.

🔸990,000 new infections/day
🔸1 in every 330 became infected today
🔸1 in every 33 people currently infected Image My latest model run forecasts a steady decline of infections, with no variants competing for dominance against JN.1.

Jan 16 • 4 tweets • 2 min read
Wastewater update:

Biobot had adjusted their last two weekly estimates down a bit. My Nov. 30th model missed the peak number by 0.6% 😅. Numbers still very high but dropping.

🔸1,270,000 new infections/day
🔸1 in every 26 Americans currently infected
Image This model was made on Nov 30, when our last biobot data point was from 11/22, 5 full weeks out from the peak readings.
Dec 17, 2023 • 4 tweets • 1 min read
In my opinion, 68% XBB is misleading. TODAY it's already less than 50% and dropping like a rock. People probably don't care what the situation was 3 weeks ago.

They want to know what's happening *now* and what is going to happen.

No mention of the fast growth from JN.1. This is very simple to explain. The BA.2.86 descendent JN.1 is quickly outcompeting and displacing the XBB sublineages, and is pushing metrics upwards in many countries.

Why are we dancing around the facts?
Dec 17, 2023 • 5 tweets • 2 min read
This is why we haven't changed Pirola's name for JN.1. This quick evolution was actually predicted by our team as part of Pirola. Even the exact site it needed (S:455) was predicted by members of this team (see @SolidEvidence quote in next tweet from September) BA.2.86 was able to compete equally with any of the fastest lineages out there, even though it was still very weak against class 1 antibodies. Marc Johnson noted the 455 mutation would give Pirola its full potential, before it even evolved.

Dec 15, 2023 • 4 tweets • 2 min read
I can help explain with models why trajectory changes "around 50% prevalence" from a growing escape variant/group and why it's a useful *rule of thumb*.

Plot it on a log chart. 40-60% is where the elbow is. Doesn't guarentee a wave, but a change in trajectory, absolutely.

Image
Image
Image The faster the growth, the *sharper* the elbow. Slower growth? Weak elbow. Multiple variants growing at different speeds? Multiple smaller elbows. JN.1 has enough growth to push numbers up in most countries.
Image
Image
Nov 29, 2023 • 4 tweets • 1 min read
Emergency room visits for Covid seeing a sharp increase in Ile-de-France, where Pirola (JN.1) has recently gained dominance.

We've been expecting this while we watched JN.1 grow. Image We also see new hospital admissions increasing. The Pirola wave has arrived in Ile-de-France.

Note the data source unfortunately only goes back to week 52 of 2022. Image
Nov 18, 2023 • 4 tweets • 2 min read
Why did XBB.1.5 not cause as big of an impact as BQ or the F456L group this summer, though it had a stronger growth advantage? I think we have some answers.

First off, it hit at an ideal time, right after the holiday surge, but I don't think that's the full explanation.

1/3 Image We also have to consider why each variant has growth advantage.

XBB.1.5's "trick" was that it had better ace binding, not that it had better immune escape. So it didn't open up a new pool of susceptibles, it just cleaned up the current pool faster.
Oct 21, 2023 • 6 tweets • 2 min read
We now have updated data from the CDC and Biobot to compare to the forecasts I've put out. This thread are the results vs model, including all my models from earlier this year.

Please evaluate to check my forecast accuracy!

First, the hosp "range" near the peak. Image Next, an "true infections/day" wastewater calibration forecast. Current numbers are almost spot on from my forecast after 3 additional weeks of data. As I expected, the "upswing" in late Sept. was a mirage. Image
Oct 17, 2023 • 5 tweets • 2 min read
#JN.1 #Pirola is demonstrating strong growth in France, where its been found most frequently. At 2% by Oct 2.

These estimates tend to skew high early with a new variant.

To me it looks likely >100%/wk, which would make it more than twice as fast as anything else out there. Image We are also seeing it outcompete the baseline BA.2.86.1 quickly in France. Now more than 50% of Pirola in France are JN.1, in just a few weeks.

If >100% holds, JN.1 could drive a wave in France as early as mid November.

More data can change that timeline. Image
Sep 25, 2023 • 5 tweets • 2 min read
There's a new study claiming no increased risk of new any type infection after covid infection. I don't have a strong opinion on either side of this argument at this point. Let's take an objective look at what this study actually shows (TLDR, it's poor): academic.oup.com/cid/advance-ar… Right off the bat there is a glaring issue. As @DGBassani points out, the control group (uninfected) has more than 3x the deaths as the covid infected group. And there's more, far more comorbidities and +5 years. That's a terrible control group.
Image
Sep 22, 2023 • 4 tweets • 2 min read
BA.2.86 Pirola's global growth advantage is becoming more clear. I excluded South Africa's data (way too messy), and the UK care home cluster.

Estimated weekly advantage is 74%, with a 50% CI of 56-96%.

If this holds, it would suggest Pirola outcompetes the strongest FLips. Image The biggest uncertainty to me still lies in the randomness of sampling. It's unclear it some samples are being sequenced due to SGTF, or more importantly, if that has changed in the past month.

Data pulled from @Mike_Honey_ 's datavis app.powerbi.com/view?r=eyJrIjo…
Sep 14, 2023 • 4 tweets • 2 min read
September 14th US update:

Community spread of Covid still "high", but decreasing after the peak. Current estimates:

🔸650,000 new infections/day
🔸1 in every 510 new people were infected today
🔸1 in every 51 people currently infected Image The decrease is mainly driven by the south, which is seeing a sharp decline in WW. Other areas of the country seeing stabilizing of cases.

Population infection estimates below: Image
Sep 11, 2023 • 5 tweets • 2 min read
Forecast out to mid October:

Prediction is difficult at the moment with a lot of factors at play, so this is a range for now. Peaks are always hard to predict.

Lower model run peaks this week. FLip is growing, but not fast enough to peak later than late Sept. Image FLip, and HV.1 with L452R (last seen in Delta and BA.5*) are growing, with HV.1 and HK.3 being the fastest at the moment. They probably won't come into play until late Oct/Nov, likely starting a new wave.

Still waiting to see how Ba.2.86 Pirola evolves and moves.