Welcome to The Nonlinear Library, where we use Text-to-Speech software to convert the best writing from the Rationalist and EA communities into audio. This is: Covid 2/10/22: Happy Birthday, published by Zvi on February 10, 2022 on LessWrong.
Happy birthday. This week CNN’s home page literally led with a story about a boy trapped down a well, then pivoted to Olympic coverage with a side of continued complaining about Donald Trump. Two years into the pandemic, we have normality.
Well, almost. There’s still a bunch of unnecessary restrictions in place and various arguments about them. That is going to go on for a while. The BA.2 variant is going to take over, although I doubt it will cause major issues as it does. There’s also that whole convoy situation.
Still. With notably rare possible exceptions, there’s nothing we can’t cope with. For those worried about Long Covid, I wrote The Long Long Covid Post.
Thus, I’m going to take this week’s title to actually say: Happy birthday, dad.
Executive Summary
BA.2 will take over as dominant subvariant but likely changes little.
Deaths finally in decline.
Cases declining rapidly.
Let’s run the numbers.
The Numbers
Predictions
Prediction from last week: 1.49mm cases (-40%) and 18,000 deaths (+2%).
Results: 1.40mm cases (-43%) and 17,028 deaths (-3%).
Prediction for next week: 900k cases (-36%) and 14,700 deaths (-13%).
I see a few signs the decline in cases will slow as people adjust, including that the places in most rapid decline now have a much smaller share of remaining cases, and also there’s no reason to expect substantial speeding up from here so on average things will slow.
On deaths, we saw a slightly premature decline due to the Midwest peaking early. We’re looking at about a 20% decline in three-week-old cases, so we should see a modest decline here but the meteoric drops shouldn’t start until the week after next. Then again, we don’t know much about Omicron’s timing, so I am ready to be surprised.
Deaths
The Midwest dropping now seems early, which is likely why the number came in slightly low. The descent starts now. Once it does, the calls for lifting what restrictions remain should rapidly get louder.
Cases
In true case numbers news, here’s a study of unvaccinated measures how often they previously had Covid:
Of 1580 individuals invited to undergo serologic testing, 816 (52%) did so between September 24, 2021, and November 5, 2021. Participants had a mean age of 48.0 years, 421 (52%) were women, and 669 (82%) were White (Table). Fourteen percent reported routine mask use in public. Anti-RBD and anti-N antibody presence/absence were correlated (95%; Cohen κ=0.908).
Among 295 reported COVID-confirmed participants, 293 (99%) tested positive for anti-RBD antibodies (≥250 U/mL, 44%; ≥500 U/mL, 27%; ≥1000 U/mL, 15%). A median of 8.7 (IQR, 1.9-12.9; range, 0-20) months passed since reported COVID-19 diagnosis. The median anti-RBD level among those who tested positive was 205 (IQR, 61-535) U/mL. There was no evidence of association between time after infection and antibody titer (0.8% increase [95% CI, –2.4% to 4.2%] per month, P = .62) (Figure).
Among 275 reported COVID-unconfirmed participants, 152 (55%) tested positive for anti-RBD antibodies (≥250 U/mL, 18%; ≥500 U/mL, 12%; ≥1000 U/mL, 6%). The median level among those who tested positive was 131 (IQR, 35-402) U/mL.
Among 246 reported no-COVID participants, 11% tested positive for anti-RBD antibodies (≥250 U/mL, 2%; ≥500 U/mL, 2%; ≥1000 U/mL, 2%). The median level among those who tested positive was 82 (IQR, 19-172) U/mL.
So that’s:
11% of those who reported no Covid.
55% of those who reported unconfirmed Covid.
99% of those who reported confirmed Covid.
Sample collection here was beyond uncontrolled so we can’t say anything about sizes of the populations or that the samples are representative of the populations involved, so large error bars, but the headline measures seem right. Almost no false positives among confirmed tests...