Four of them cause the "common cold" (229E, NL63, OC43, HKU1).
The three most recent are deadly (SARS-CoV, MERS-CoV, SARS-CoV-2).
All three of the deadly ones use the ACE2 receptor. Only one of the common cold viruses (NL63) does.
We have never in the history of our species encountered a situation anything like this one, with a coronavirus that is infecting *billions* of hosts, year-round, repeatedly up to several times per year, and being transported all over the world through mass global travel.
In short, we cannot simply look to other human coronaviruses and draw conclusions about what SARS-CoV-2 will do longer term.
SARS-CoV-2 has already proven itself not to be a "textbook virus". Rather, the textbooks will need to be revised significantly because of it.
Also, here's a reminder that the following are *myths* / *misconceptions*, with no basis in either experience or theory:
β That viruses always automatically evolve to become benign so they don't drive their hosts extinct.
Myths / misconceptions cont'd:
β That humans have evolved alongside pandemic-level respiratory viruses for millions of years. That's bats. We're not bats.
Myths / misconceptions cont'd:
β That a virus like SARS-CoV-2 evolves slowly or will soon run out of evolutionary space. This neglects the fact that there is an absolutely enormous population size of the virus and that it is evolving in a changing fitness landscape.
Myths / misconceptions cont'd:
β That a pathogen becoming endemic means it is no big deal. Also endemic: malaria, tuberculosis, measles, etc.
β That the immune system is like a muscle that gets stronger with repeated infections and weaker if not exercised through exposure to *pathogens*. Don't confuse this with the "hygiene hypothesis", which is about exposure to *commensal* microbes.
In the same way that we cannot make assumptions about the evolutionary trajectory of SARS-CoV-2 or the effects of (and on) immune systems, we need to reject expectations built on myths and misconceptions.
Every day there are new discoveries about what SARS-CoV-2 does to our bodies. Those proclaiming an end to waves have been proved wrong over and over. Optimistic predictions about the mildness or lack of potential spread of new variants have not survived collisions with reality.
We do not know what SARS-CoV-2 will do.
There is no simple, linear evolutionary path that it must inevitably follow.
There is no precedent on which to confidently base predictions.
What we can say with some confidence is that more virus is a bad thing.
Quick correction:
MERS-CoV uses the DDP4 receptor, but close relatives of the virus do use ACE2.
The point remains that the deadly viruses are not obviously just cold viruses we're not used to yet.
Two new variants are competing for dominance: NB.1.8.1 and XFG. We recently nicknamed NB.1.8.1 "Nimbus", and it's pretty clear that XFG deserves a nickname as well. Keeping with the meteorological theme, XFG = "Stratus".
Here's some more info about Nimbus and Stratus. π§΅
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There are two main ways by which divergent variants may evolve within single hosts: evolution during chronic infection and recombination during simultaneous infection with more than one variant. Nimbus (NB.1.8.1) and Stratus (XFG) have both mechanisms in their ancestries.
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Stratus (XFG) is a recombinant of LF.7 x LP.8.1.2 -- both of which descendants of BA.2.86, which itself had evolved within someone infected for ~2 years.
Nimbus (NB.1.8.1) is getting a fair bit of attention, but it's not the only SARS-CoV-2 variant worth watching. Here's a link to info about a few more, all of which have arisen either through within-host evolution during chronic infection and/or within-host recombination.
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First, a reminder that Nimbus (NB.1.8.1) is a triple recombinant with both BA.2.86 and XBB ancestry -- that is, it has multiple recombination events and chronic infections in its evolutionary history. Here's a thread I wrote about it:
The last variant to receive an informal nickname was BA.2.86 "Pirola" nearly two years ago, back in August 2023. Since then, it has been a prolonged "variant soup" phase, with descendants of BA.2.86 arising, gaining prominence, and then falling in frequency.
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A prolonged variant soup phase involving the Pirola clan does not mean there was no within-host evolution occurring. It just meant that nothing had gotten back into the general population that could compete with the many, many descendants of BA.2.86.
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BC was where the NDP did best last election, and this time it went Lib and Con.
So, we essentially traded a Liberal minority with progressive parties being very influential to a Liberal minority with a huge Conservative opposition and minimal progressive representation.
The fact that 41.4% voted Con (vs. 43.5% Lib) isn't a good sign either.
Yes, I'm relieved that it's not Poilievre as PM and I'm glad he lost his seat. But beyond that, we're not in a very good place overall. The major rightward shift isn't going to be good, especially when the Liberals eventually lose to the Conservatives.
It's very important to be clear about what is happening in the Canadian election and how progressives need to approach it. π§΅
The LPC surge toward a majority is due primarily to a collapse of support for the NDP and Bloc, and much less so a drop in support for the CPC.
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This means that the Libs are mostly picking up progressive voters who are planning to vote strategically to stop the Cons. They are not picking up huge numbers of "moderate conservatives".
Cons support is generally committed but Libs support isn't.
Thoughts on pandemics, inclusion, annexation, Indigenous issues, climate, genocide, and more and the connections I see among them. I fully acknowledge that I am writing this from a position of substantial intersectional privilege.
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I really hoped that the (ongoing) SARS-CoV-2 pandemic would inspire us to make meaningful, positive changes in society. Indeed, early on it seemed like privileged people finally understood what it was like to lack access to things we otherwise take for granted.
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Sadly, but perhaps predictably, we instead rushed back to the status quo as quickly as we could. If anything, things are worse now in terms of public health, accessibility and inclusion, and global health equity. Infectious disease has been actively normalized.
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