Post #1369: COVID-19 trend to 12/27/2021, not quite a new record

Posted on December 28, 2021

I thought that we’d break the U.S. record for daily new COVID-19 cases today.  But we’re just a touch short.  Looks like we’ll almost certainly break it tomorrow.

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 12/28/2021, 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.

The good news is that the official hospitalization counts out of the CDC show no proportionate rise in hospitalizations.  Note that, as scaled, this is the first time in the pandemic where the hospitalizations line is below the new cases line.

Source:  CDC COVID data tracker.

You’re going to see people dismiss this as “too soon to tell”, but my best analysis says that’s incorrect.  (Or, for that matter, just look at the peak from January — looks like the lines were pretty much in sync then.)  I went over all this a coupe of posts ago.  There are significant lags between (e.g.) infection, symptom onset, and hospitalization.  But that’s not the point.  Near as I can tell, on average, for the two lines shown above, reported new hospitalizations lag reported newly diagnosed cases by one day, on average.

For sure, people are still being hospitalized and dying.  But at a lower rate, per case, for Omicron than for prior variants.

The problem is, while the hospitalization rate is lower, it doesn’t appear to be anywhere near as low as early research suggested.  But I think I have the answer for that, in the next post.

That said, this wave isn’t stopping, it’s continuing to accelerate.  And before the words “post-Christmas-surge” leave your lips, please note that a) this wave started before Christmas, and b) owing to the typical lag between infection and reporting, the cases showing up today were infected well before Christmas.

My expectation of a short, sharp wave, based on what occurred in South Africa, appears incorrect.  Sharp, yes.  But so far, no strong indication that this is going to be sort.  South Africa and Norway did indeed have a short, sharp peak.  Great Britain and Denmark did not.  As of today, it looks like the U.S. is going to fall into the “not” group.

We can hope that this last uptick is some sort of reverse holiday effect.  Maybe a lot of people decided to get tested before joining relatives for the holidays.  If so, that would be unique to this year.  That certainly didn’t happen last year.  But if so, that will wash through the data in just a few days.

As you can see from this final chart, cases are up in all regions.  The daily new case rate has not-quite-doubled since the start of the Omicron wave on 12/17/2021.