Post #932: The new British strain of COVID-19.

Posted on December 30, 2020

With so much bad news in my face every day, it’s hard to tell what’s really dangerous from what’s just run-of-the-mill awful.   I get to the point where I just shrug stuff off if it doesn’t directly affect me and mine, here and now.

They’ve been having an exceptionally tough pandemic December in the United Kingdom.  New lockdowns, border with France closed, case counts rising.  And that has something to do with a new, worse strain of COVID.

But so what.  Things are tough all over.  How bad can it be, really?

I started out today to try to post something light.  But what I most wanted to understand, right now, is this new British strain of COVID-19.  The one that’s supposed to be so much more infectious. And the way to learn about it is to try to understand it well enough to explain it, in writing.

This is just Part I of that post — just my conclusions about this new British strain of COVID-19.  The more I look, the more concerned I get.  So here, I’m just going to state what I believe to be true, after a couple of hours of trying to make my way through the research behind this.  I’m going to come back with a second posting giving citations as to source, and so on.

The short answer is that this appears to be a major problem.  It’s significantly more infectious than existing strains.

If the old variant yielded (say) 1.1 new infections from every infected person, the new variant would yield about 1.5.  Doesn’t sound like much, but that’s a material difference.  It’s the difference between keeping this under some sort of control and not.  Or, to put it another way, it makes it just that much harder to avoid having COVID cases overrun our health care system.

It’s not deadlier.  It doesn’t appear to lead to more severe illness.  Likely, any vaccine that protects against the existing prevalent strains will protect against this new one.

But it’s a lot better at spreading.  And it’s out-competing the other strains in Britain, because of that.

I judge the evidence for that conclusion to be quite strong, in the sense that many independent lines of evidence all give the same answer.  That’s based on everything from laboratory experiments (to see how easily it infects cells in a test tube), to epidemiological modeling (back-solving for the transmissibility by fitting models to the observed data), to the simple fact that this new strain is rapidly becoming the dominant strain in and around London, as case counts there spike.

It’s here in the U.S.  It has been detected in “community spread” in Colorado.  That’s a term-of-art in epidemiology, and it’s important.  That phrase means that nobody has any idea where the infected person picked up the infection.  Which suggests that it’s already out in the community.

You probably don’t recall, but at the very start of the pandemic, a lot the news reporting focused on the first “community spread” case in any given area.  You can see that in small type in Post #621.  That first “community spread” case is important, because that’s the point at which you can no longer hope to stop the spread by quarantining infected individuals.

And so, by analogy, given that they’ve found their first community spread case here, there’s essentially no way to prevent this from spreading in the U.S. now.  As with the start of the pandemic, right now, we only know of a couple of cases in the U.S.   But we have no way to stop it now.

And it’s in Canada, much of Europe, and (possibly) Japan.

The fact that it hasn’t been detected elsewhere in the U.S. may not mean much, as we don’t do much genetic sequencing of COVID samples in the U.S.   Could mean it isn’t widespread.  Could mean we haven’t looked very hard.  It’s too soon to tell.

The one thing I see in our favor, compared to the British, is timing.  This is hitting Great Britain at the peak of COVID seasonality.  But it took fully three months get there — from the first detected cases (September), to being well on its way to being the primary strain in the London area (now).  And it is still the minority strain in most of Britain outside London and adjacent areas.

If we follow the same path, then, this new strain will start to predominate in some localities in early Spring.  Which should be when the natural seasonality of coronavirus results in a reduction in new cases.  Maybe we’ll get some help from that.

I’ll write more on this once I think I understand the research.  Or, at least, understand it as well as I’m going to understand it.

Let me put it this way.  My recent prediction, based on recent trends, is that the U.S. is over the hump on COVID-19.  This doesn’t make me change that prediction, yet.  But I’m definitely rethinking it. Everything I said was based on looking at what had already happened in the US, given the currently circulating strains.  Once you add in a new strain that is far more readily transmitted, it’s not clear that history is a good guide as to what happens next.

FWIW, the research that provides the most recent estimate of transmissibility is here.  It is a tough read.  And it’s not that I think epidemiological modeling like this is hugely accurate.  But, given the estimate, and the other lines of research suggesting the same thing, it only has to be in the ballpark to make this a significant problem.