Today's Numbers:
๐น 1.27% (1 in 78) are infectious
๐น >600,000 C0VID cases/day
๐น>30,000 #LongCovid cases/day
We will pass the late-summer wave's peak in just over a month.
1/
The different forecasting models reach a strikingly similar conclusion about where we'll be in a month: very bad.
November 27 by the Numbers:
๐น 1.76% (1 in 57) are infectious
๐น >800,000 C0VID cases/day
๐น>40,000 #LongCovid cases/day
2/
Forecasting nuance:
Alt Model #1 (turtle) thinks the current real-time numbers are an underestimate, and it ignores the most recent week's data. Alt Model #2 (cheetah) accounts for recent errors in the real-time numbers; with low error, it maps on very closely to the real-time (red) line. The black line shows the composite used for reporting estimates. Note, everything converges in 4 weeks.
Zooming out to the full pandemic, you can see that we are entering the 8th wave.
Today, there is more transmission than during 50.6% of pandemic days. It's a coin toss as to whether any particular day of the pandemic has had more or less transmission than today. ๐ท๐ 3/
Although we're about to exit the valley between the 7th & 8th waves, transmission is still very high. Large groups amplify transmission.
For example, in a group of 20-25, there's about a 25% chance someone would have infectious C19. In a large lecture hall, it's assumed.
4/
Here's the danger of a Thanksgiving gathering in the U.S. (Nov 23). Many people are finalizing holiday plans now.
In a large family gathering of 15-20 people, there's about a 25% chance someone would be infectious.
I am quite confident in these numbers.
5/
Here's the possible danger of a Christmas gathering in the U.S. (Dec 25).
I am exceedingly cautious on posting long-range forecasts. They are speculative and do not account for the highly-valuable near-term fluctuations that can occur, particularly if there's an immune-evasive variant. Take these as my best point estimates nearly two months out, for illustrative purposes just so people get an idea of how bad things may be. Many people are booking trips now, so these rough estimates may be useful.
In a small gathering of 9-10 people, there's about a 25% chance someone is infectious. Once you start looking at large family or multi-family gatherings that span 20-25 people, you basically begin to assume someone has infectious C19.
6/
Here's the full PMC Dashboard for Oct 30.
You can read the full report at
Please share across other social media platforms. Much appreciated. ๐
New #LongCOVID article out today in one of the top science journals, @Nature.
The most striking finding to me was that more frequent vaccination reduced the risk of yearlong LC from the 4.3-5.2% range (in their sample, which is low) to just 0.38%. That's a >10x reduction.
1/
Their sample is at the low end of #LongCOVID estimates overall, so for a fairer comparison, I could imagine 20% of the under-vaccinated group with LC & about 2% in the more frequently vaxxed group.
We could quibble on the base rates, but the risk reduction is the key stat.
2/
I always advocate for multilayered mitigation because a 0.4-2% chance of a new severe disability is considerable for individuals and populations. Effects are cumulative. Also, vaccines wane, and evading variants emerge unpredictably. Forward transmission is common. Etc.
3/
PMC C0VID-19 Tracker, Oct 23, 2023
"As Good As It Gets"
U.S. #wastewater levels are higher than during 44% of the pandemic:
๐น 1.05% (1 in 95) are infectious
๐น >500,000 C0VID cases/day
๐น>25,000 #LongCovid cases/day
Fall cases bottom out in 2 days or so. 1/
Zooming out from the 6-month view to the full pandemic, note that fall transmission is bottoming out at a high rate.
The U.S. 8th wave this winter will start to pick up soon, at a fast clip, and transmission will accelerate in December.
2/
With 1.05% of the U.S. population actively infectious (Oct 23), larger group activities continue to be increasingly risky.
Expect similar numbers the next two weeks. Then, activities will get much more dangerous.
Biobot (blue) versus Verily (black) #wastewater data.
You'll see Verily data suggest the most recent wave (#7) has had considerably more transmission than Delta (#3). And that last winter (#6) was similar (or worse!) than the prior winter's BA.1 surge (#4).
Who wins?
1/
Here are the correlations among Biobot levels, Verily levels, & IHME true cases for the 1st of each month from Jan '21 to Apr '23.
Biobot correlates r=.94 (freakish) with IHME. Verily only correlates r=.67.
Either Biobot is much better, or Verily knows something we don't. 2/
The CDC awarded Biobot's contract to Verily.
Once Verily brings on Biobot's former CDC-contracted wastewater sites, that should help. Case estimation will be easier if they fold in the historic data to more accurately represent the nation.
U.S. #wastewater levels are higher than during 58% of the pandemic:
๐น 1.56% (1 in 64) are infectious
๐น >745,000 C0VID cases/day
๐น 37,000+ #LongCovid cases/day
Click the full Tweet for more details on each forecast... 1/5
Wastewater levels are up from 505 copies/mL last week to 512 copies/mL this week. Before one screams "SURGE!!!," let's dig into the details. That's about as small an increase as possible, and well within the range of data corrections to real-time reports.
The Real-time model (red line):
It assumes that real-time data reports are accurate. However, real-time data often get corrected. Biobot and the CDC are currently in a transitionary phase of modifying when and which sites report, so I take the real-time data with a grain of salt. If it is accurate, however, the model suggests a rebound in cases, peaking around Oct 11, before bottoming out around Nov 1, before cases begin rising again for the winter wave.
Alt Model #1, Turtle (green line):
The turtle model ignores the most recent week's worth of data from Biobot, treating it as unreliable. Thus, it assumes that rather than a small increase this week, levels are actually continuing to decline and that corrections to real-time reports will later reflect that. It's essentially saying that the bump you're seeing in the real-time model is just noise. Cases will stay almost completely flat the next 6 weeks, with an official low point around Oct 25, before cases begin rising again for the winter wave.
Alt Model #2, Cheetah (orange line):
The cheetah model aims to correct for biases in real-time data reports. If last week's real-time report overestimated levels by 10% upon correction, it assumes this week's real-time report suffers the same bias. Last week's real-time report was quite accurate, so the cheetah model just looks close to the real-time model, same mini-peak, same valley, same rise in November for the winter wave.
Composite Model (black line):
This is the average of the three models. It's what's used for deriving all of the statistics reported. It basically suggests that cases will be mostly level at a high rate the next 6 weeks with minor fluctuations up or down. The composite model's take-home points are 1) continued high cases the next 6 weeks, 2) minimal fluctuation on a day-to-day basis during that time, 3) a low for the remainder of the year around Oct 25, and 4) a winter wave starting to pick up in mid-November.
Next Tweet, let's examine regional variation.
Regional variation suggests the need to pay attention for an increase unanticipated by the models.
The northeast is still rising steadily, and they are seeing 3-4x more FL 1.5.1 than other regions.
Caveat: this occurs during a time of Biobot/CDC reporting delays/issues.
2/5
Zooming out from the 6-month & regional views to the full pandemic, note we're in a steady state of high transmission between the 7th & 8th waves of the U.S. pandemic.
We will likely see at least 1.4% of the population actively infectious every day for the rest of 2023.