Just thought you might want to know. Because nobody ever bothers to tell you when the news is reasonable, normal, and good.
Per CDC, US weekly new hospitalizations with COVID, for the U.S.:
The timing of the wintertime peaks (the black lines above) in COVID is extremely regular. All four of those winter peaks are January 1, plus or minus a week or so.
This is both surprising and unsurprising.
It’s surprising in that the winter peak of COVID is far more regular than the similar winter peak in flu hospitalizations. The peak of winter flu hospitalizations varies quite a bit from year to year.
Source: CDC flu data.
But if you think about it, it’s not all that surprising. Flu often has quite a different season from year to year, based on a new mix of strains being prevalent each year, and based on spread from epicenters of infection. COVID, by contrast, is pretty much the same year after year now, and it’s everywhere.
It’s also unsurprising in that these hospitalizations are almost entirely for the elderly, and hospitalization rates for the elderly, for respiratory infections, peak mid-winter every year. So that’s going to reinforce any tendency for COVID to peak at mid-winter.
That said, Virginia still tracks lab-determined cases, and the Virginia case-count data show the exactly same winter regularity as the U.S. data. This, from the Virginia Department of Health:
The peaks are again January 1 of each year, plus or minus a week or so. So it’s not merely a regularity of hospitalizations for the elderly.
Finally, I was tempted to try to make something out of the other apparently regular peaks on that CDC graph, the ones circled below:
But those are a mish-mosh. The first one is due to a new strain — delta ? – that was then suppressed by vaccines (and replaced by Omicron). The second one is more-or-less mid-summer, and so predates return-to-school for that year. The third peak is in early September. There’s really nothing to link them that I can see.
