Thread by @ASlavitt

COVID Update: a new highly mutated variant nicknamed Centaurus (BA2.75) is emerging around the world.

Even as BA.5 makes its mark in the US, Centatus has 11 unique mutations from BA.5. This gives a strong clue for what the future holds. 1/

The world we live in is one with not only continue waves, but waves so frequent that you. And see the next one emerge even as you go through the current one.

BA.5 is just taking hold in most of the country even as we see new ones emerge. 2/

Since 2020 COVID has taken us on a journey as we have learned more about it.

Our first concern was its impact as a novel virus & its asymptomatic spread. Next it was its amazing ability to mutate. Then the speed of infection. Then the ability to reinfect. Now, there’s a new 1.2/

One principal concern in fighting the virus is the clearer picture emerging of how frequently and radically it mutates and creates new waves that can drive multiple reinfections.
3/

A virus that circulates once/year is one easier for science to keep up with with annual vaccine boosters.

COVID, however, is creating new variants at the speed of the common cold but with more severe consequences. A good vaccine in January will be a lot less good by the Fall. 4/

Bill Hanage @BillHanage made the point on today’s episode of that last year at this time people were suggesting we needed a Delta specific vaccine.

Omicron put Delta in the dustbin, just as BA.5 did to Om BA.1. And Centaurus could do the same to BA.5. 5/

podcasts.apple.com/us/podcast/in-…

As Bill outlines on the episode, the conception that each variant is “more contagious” than the last is misleading and potentially wrong.

What we know for sure is the magical powers of new variants are (as the episode title suggests) their ability to evade prior immunity. 6/

Your chances of getting infected when BA.5 comes to your community are a direct result of the virus getting around immunity from past infections where the mutations are increasingly different. 7/

There was hope at one point that the virus would run into limitations of contagiousness. The virus evolved around those limits by changing something else— the mutations on the spike protein— which it can do in unlimited combinations & incredible speed. 8/

If that all feels like challenging news, it is challenging from the standpoint of our ability to run a scientific response that quells infections.

But it doesn’t threaten, at least as of now, the major gains we have made at reducing scute severity & mortality. 9/

These gains come principally from our vaccines, prior infection & highly effective treatments.

But each time we see a new variant we must ask again— is this one more or less severe than the last ones? I asked this of @BillHanage in the case of BA.5. 10/

The answer to how severe this current incarnation of acute COVID is depends on how effectively it spreads to high risk populations & how recently they have been protected.

Portugal’s older population had a much harder time w BA.5 than SA’s mostly younger population.11/

Other factors matter too. According to Bill, Omicron is on balance less severe and is met with a population with various layers of immunity.

Delta was more severe but also faced a population that had not been as vaccinated or had prior infection. If it came today, who knows? 12/

So what?

We can anticipate frequent rounds of COVID for the foreseeable future. So far we haven’t seen severity increase but many populations remain vulnerable.

As I mention on the episode I lost a cousin to COVID late last month. The numbers are down but it is very real. 13/

For those at lower risk, it means more frequent disruptions & missed work and a greater likelihood that if you get COVID you will be part of a chain leading to poor outcomes.

And every telling of what’s happening w COVID needs to focus beyond acute COVID and also on chronic.14/

You will notice that when I refer to COVID’s impact I increasingly mean to specify that things like severity matter both in the “acute” stage and the “chronic” stage. Our language needs to accommodate long-COVID not as an after-thought but an upfront risk of contagion.15/

So far less severe acute COVID seems to correlate w less severe or likely chronic COVID. So far better vax protection seems to reduce instances of long term COVID.

But things are too new & our data too incomplete to know for sure. And each new variant requires a fresh look.16/

Smart policies will bring mandatory masking back as often as needed. I live in a community that does. And it’s hardly too much to ask to protect people at near constant risk of getting sick, missing work, or worrying about long term illness or death. 17/

What no one seems to want to talk about is the frequency/the constant bombardment of new variants.

To do so would be to admit that there is no scientific way to keep up or stay ahead. And that protecting ourselves & others requires us to do something ourselves. /end

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