Puzzling Omicron wave stats
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Since this week marks the second anniversary of the Epstein Awards, given in recognition of outstanding performance in the field of amateur epidemiology, let’s look at some curious COVID stats. Going back 14 months to last winter, we’ve had three distinct waves of COVID, peaking in January, September, and then January again.
The curious thing is that the Case Fatality Rate (CFR) at the peak of the latest wave was about a quarter of what it was during the previous two waves — but this improvement has not been sustained during the current trough. Two months after the peak of the Omicron wave, we’re back to the same CFR we were at pre-Omicron.
Stats
Peak deaths tend to lag peak cases by around 16 days. Here are the various peaks and troughs of the three waves, with the current trough extrapolated out 16 days at the end. All numbers are seven-day rolling averages:
January 11 2021: 258K cases
January 27: 3468 deaths
1.34% CFR
June 22: 12.2K cases
July 6: 251 deaths
2.06% CFR
September 1: 168K cases
September 16: 2026 deaths
1.2% CFR
October 29: 73K cases
November 13: 1,100 deaths
1.5% CFR
January 13 2022: 822K cases
January 29: 2700 deaths
.33% CFR
February 24: 78K cases
March 11: 1,073 deaths
1.38% CFR
March 11: 36,800 cases
March 27 (projected): 475 deaths
1.3% CFR
I suspect the somewhat higher CFR last summer was due to misleadingly low case rates being recorded at that time, as the pandemic seemed over for a few weeks there.
The big question is: why are we back to the 1.2%-1.5% CFR baseline, after the massive plummet in the CFR during the peak of Omicron? Is the Omicron strain still not the dominant strain in the USA at the moment? What other factors might be at play that would explain this pattern?
ETA: Thinking about this a bit more, commenter busker type’s observation that current official case totals might be very misleading for the same reasons they were probably very misleading last summer (people just stopped getting tested) is likely correct.
Note too that the current trough, which is producing the lowest case rates since last summer, would still yield, given current CFRs, an annual mortality total of about 175,000 COVID deaths, if it were to be sustained for an entire year.