Post #1408: COVID-19 trend to 1/20/2022. Everything remains on schedule

Posted on January 21, 2022


The Omicron wave appears to be unfolding on schedule in the U.S., plus or minus a few outlier states.

The U.S. east coast (Northeast and South Atlantic regions) led the way on the upswing.  Ten days ago, those regions had the highest  new case rates in the nation.  Now they have the lowest.

By contrast, the entire mid-section of the country started later, and is still more-or-less in the upswing portion of this wave.  Those regions are only now starting to top out.

The net result of all of that, for the U.S. as a whole, is that new COVID-19 cases fell seven  percent in the past seven days.


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 1/21/2022, from”  The NY Times U.S. tracking page may be found at

I’ll be resetting my charts to start with the Omicron wave, which I date to 12/17/2021.  As shown above.

Characterizing the downslope of the Omicron wave

If this wave sticks to the schedule, it’s going to be months yet before the COVID-19 new infection rate is down to where it was last summer.  Just how long that will take is difficult to guess.  But so far, there is some similarity in the rates of decline in new cases following the peak, among countries (or large U.S. states) that have peaked.

South Africa is now four week past their peak, and new case rates are down to about 20% of the peak rate.  That’s the result of two weeks of rapid decline, and two weeks of a slower rate of decline.


The United Kingdom is now two weeks past their peak, and new case rates are down to about 50% of the peak rate.  It now looks like the rate of decline will be slowing.

Canada is (arguably) two weeks post-peak, and new case rates are down to 50% of the peak rate.  But unlike Great Britain, the rate of decline does not year appear to be leveling off.

I have ignored the the rest of the Southern Hemisphere (outside of South Africa) prior to this, but I now see that Australia had a far worse Omicron outbreak than the U.S. did, on a per-capita basis.  They now appear to be one week post-peak, and cases are at 75 percent of the peak level.

Australia is interesting for U.S. residents for a couple of reasons.  First, like South Africa, it’s summer there, which validates that weather likely plays only a minor role (if any) in the Omicron outbreak.

Second, the country is just about exactly the size of the U.S. excluding Alaska.   Accordingly, there’s some spread in the timing of the peaks in their various states.  Looking at the graph, Queensland peaked just a couple of days ago, and South Australia has not yet peaked.   So, plausibly, their overall peak might get smeared a bit over time, as we would expect for the U.S. peak, owing to differences in timing by geography.

Another oddity I can’t help but notice is that, unlike the U.S., where Omicron is everywhere, COVID-19 new case rate vary wildly across Australian states.  Western Australia has about 2.7M residents, but is only getting about 10 new COVID-19 cases per day, for a rate that’s well under 1 case / 100K /day.  (I now see that Western Australia has taken this with the utmost seriousness, including closing the border to the rest of Australia.)

Finally, there’s New York, which has about 80% of the population of Australia but less than 2 percent of the land area.  Of all of the places shown, New York has the fastest rate of decline.  They are below 50% of their peak, roughly 1.5 week post-peak, with no indication of that slowing down.


At the end of the day, I’m guessing that the rate of decline for the U.S. as a whole will be slower than the rates shown above.  We have a larger population, spread across a fairly large area.  Omicron cases rates are high everywhere, and peaks will occur at different times in different states.  That said, if individuals states follow the path being set in New York, Omicron should clear pretty rapidly within any one states.  Which means that life might get closer to normal within a relatively short period of time.