Post #1140: COVID-19 trend to 5/8/20201, down and accelerating

Posted on May 9, 2021

The rate of new COVID-19 cases per day is now 41% lower than it was at the peak of the U.S. fourth wave.  The rate of decline continues to accelerate modestly.

In early March, it was clear that the U.S. fourth wave was going to shape up as a race between vaccination and the more-infectious COVID-19 variants.  When I did the math, I predicted that vaccination would win (Post #1051, March 11, 2021).   And I think vaccination, plus the large fraction of the population that had already been infected, plus maybe a little help from the seasonality of the coronavirus itself, explains the current situation.

I hope to see all the pundits who prophesied a catastrophic fourth wave confess their error, publicly, forthwith.  Starting with the author of the completely analysis-free and fact-free statement regarding an impending sense of doom.  (/s).

Here’s the U.S./regional chart.

Beyond that, sometimes you just see what you want to see.  The brain seeks patterns even in random data.  But in this last week, I think I’m seeing a lot of states begin to exhibit some very sharp downward trends.  The charts have an unusual number of little downward-facing tick marks at the ends of the lines.  Which is tough to do, given that these are all seven-day moving averages, and so are constructed not to show swift changes.

I’m not even going to circle the ones I’m seeing, but have a look and make your own judgment.  Maybe this is just a natural consequence of being on a downward trend.  But it’s what stood out of the data when I looked at these most recent graphs.  Here are the six regions, from Northeast to Pacific.

Two more things to say.

Speaking of a false sense of impending doom, I think that two more things need to be said.  They both relate to a natural tendency to extrapolate the future based on recent past experience.

First, regarding COVID-19 variants:  Have you noticed that we haven’t had any new ones, to speak of, in a while?  Or, for sure, we haven’t had some new super-strain pop up that’s markedly worse than, say, the U.K. variant that is now the norm for U.S. new COVID-19 cases.

It’s as if this new COVID-19 strain went through one round of evolution, found all the mutations it could exploit to make itself more effective … and then stopped. Which, given how many active cases there are, suggests to me that maybe it has reached the limits of its technology.  Maybe there are no single-gene or few-gene mutations that can make this disease any more effective than it already is.

My point is that when the first few prevalent new variants arose, there was a natural tendency to think that this was just the start of a trend.  Many pundits then began to use this for standard fear-based journalism, to suggest that the virus was going to continue to evolve, at that same pace, producing ever-more-virulent versions of itself.

But that was just guesswork.  And, frankly, it suggested a behavior typically not observed in other common viruses.  Every flu season we get different flu viruses, but not necessarily worse ones.  And flu has had centuries to evolve.

As long as everybody gets to guess, here’s my guess.  Maybe the COVID-19 virus has already evolved to be as bad as it can be.  Maybe there’s a limit to how infectious and deadly it can become, given its basic genetic makeup.  And maybe it has reached that limit, given the (guessing) quintillions of replication attempts it has had over the past year.  Maybe it has already fully exploited the capabilities of its genome.  Maybe in the course of this past year-plus, it made all the improvements in itself that its ever likely to find.

Maybe it’s already as effective as it can get.  And if so, all the speculation about ever-increasing virulence of COVID-19 is just that — speculation.  Maybe we took a one-time jump in infectiousness, between the original and the current variants, and misinterpreted that as the start of a trend.

Second, regarding the rate of vaccination itself, maybe it’s too soon to toss in the towel.  We can see the dropoff in the rate of vaccinations from the CDC data.  And that’s disheartening, for sure, given that under 60% of adults have been vaccinated so far.

But we all have a natural tendency to look at the line and extrapolate.  To say to ourselves, heck, give that another month and nobody will be getting vaccinated.

I think it maybe a bit too soon to say that, just yet.  Sure, as COVID-19 ebbs away in May 2021, people are going to be less motivated.  So, in effect, the success of vaccination so far is choking down the rate of new vaccinations.  And, as with herd immunity, the un-vaccinated are being protected by the vaccinated.

But maybe we’ve just seen the passing of the wave of truly motivated individuals.  And now the slackers will get theirs, at a slower but steady pace.  Maybe this won’t drop to zero in a month.

In addition, recall that COVID-19 appears to be a strongly seasonal virus.  Let’s not lose sight of what the shape of the full pandemic looked like in the U.S.

Come October of 2021, if the virus is still in circulation, and there’s a large fraction of the population that’s still not immune, it’s a pretty good bet we’re going to have fifth U.S. wave of COVID-19.  And if that happens, and those case counts start rising again, just before the holidays, maybe that still-vulnerable un-vaccinated population will have a change of heart, and consider finally doing what they should have done months earlier:  Get vaccinated.