No real surprises. The U.S. is now down to 24 new cases per 100K population per day. That’s down just 37% in the past seven days (versus a steady 40%+ since the end of January).
Data source for this and other graphs of new case counts: Calculated from The New York Times. (2021). Coronavirus (Covid-19) Data in the United States. Retrieved 2/24/2022, from https://github.com/nytimes/covid-19-data.” The NY Times U.S. tracking page may be found at https://www.nytimes.com/interactive/2020/us/coronavirus-us-cases.html
It’s not clear whether that slowdown in the rate of decline is significant or not. It’s barely visible on the log-scale graph, where the straight line represents a constant percentage rate of decline.
One reason not to take this latest rate of decline too seriously is that many states are busily tidying up their records, and thereby screwing up the reported case counts. On paper, Maine now has a huge case load, while Washington State has virtually none. Both of those are due to “catch up” corrections in their reported counts. I’m sure there must be others that just didn’t catch my eye. If I toss out those two strays, I’m not seeing any real curvature in the plot of the individual states.
We still have about 1500 deaths and 6000 new COVID-19 hospitalizations per day. That’s far above the rate we would have expected, given the new case counts and the presumably milder Omicron variant. The main cause of this seems to be a shift in cases toward the elderly, which may be signalling that immunity from the last big round of vaccinations is beginning to wane.
Source: CDC COVID data tracker
What a difference a year makes doesn’t make.
In an odd historical note, we’ve almost reached the new case level that we had at this time last year.
But that just drives home how oddly high the current new hospitalization and mortality rates are. At this time last year, we had only just begun vaccinations, and we still faced the native (B) strain of COVID, which appeared to be more virulent than the current strain.
Source: CDC COVID data tracker
In other words, any way you look at it, the situation last year should have been far worse than the situation now, for the same number of cases. Almost nobody was vaccinated, and the strain in circulation at that time was more virulent than what’s going around now.
(One possible explanation might be some massive under-reporting of new cases at that time, relative to the present. But the U.S. had largely resolved any shortages of tests by that point in the pandemic, so I don’t think that’s a significant factor. And they didn’t have home test use preventing some fraction of new positives from entering the official statistics.)
And yet, here we are with about the same number of cases being recorded, with a less virulent strain, with far higher rates of vaccination — and the hospitalization rate is the same as it was a year ago.
Source: CDC COVID data tracker
But I keep forgetting that this still largely remains a pandemic of the unvaccinated. At least as far as hospitalization and death are concerned. Here’s the CDC’s estimate, ending in early January 2022, of the relative rates of hospitalization by vaccination status, at that time.
Source: CDC COVID data tracker.
If I apply those rates to the fractions of the U.S. population, you can see that, even now, the tiny slice of the population that refuses to get vaccinated still accounts for the majority of the serious illness from COVID-19. Even now — as of January 2022 — more than half the COVID-19 hospitalizations in the elderly were from unvaccinated individuals.
Source: Calculated from population and hospitalization data from the CDC COVID data tracker.
Which, in the end, brings me back to COVID-19 hygiene, or what’s left of it. If you’re an unvaccinated elderly person, the only thing that stops you from getting COVID-19 is the COVID-19 hygiene practices of you and those around you. That, and the luck of the draw. And here’s how that level of protection looks, for the U.S. population, now versus one year ago:
Source: Carnegie-Mellon University COVIDcast.
If anything, you might guess that the unvaccinated are at higher risk of infection now than they were one year ago. Today, few are taking any real pains to keep the unvaccinated safe. Whereas, last year at this time, we were almost all unvaccinated, and most people applied at least rudimentary hygiene practices.
In any case, it will be interesting to see how these numbers change as the CDC gets around to updating them through the decline portion of the Omicron wave. If, within the elderly, we see an increasing share of new hospitalizations among the vaccinated population, that will be a pretty clear indication that, as hypothesized, the Omicron case hospitalization and case mortality rates are increasing because the last round of vaccines is starting to wear off.
