(2021-12-23) ZviM Omicron Post #9

Zvi Mowshowitz: Omicron variant Post #9. There are three major fronts. There’s the question of what is happening and how many cases we have, there’s the question of how people are reacting and will react to it, and there’s the question of severity.

On the case front, it looked like the UK might have peaked, which would be big, but it now looks like that was premature

On the severity front, we have a lot more data. As far as I can tell, it mostly tells a consistent story of modestly reduced severity for infection in a given individual (after controlling for everything) in the 30%-60% range, which will help a lot but is no match for exponential growth. I’d love to be conclusive, but it’s all super complex and convoluted. That’s what the bulk of this post is about.

On the reaction front, there have been a lot of extreme reactions to the Omicron situation, by individuals. I’m hearing and noticing a lot of folks deciding to lock it down for themselves. Many of them are doing so in order to ensure they can still have their family Christmas, which seems like an excellent reason even if one is not personally worried

Best Possible News?

The tricky part is knowing what is good news, and what is bad news. So you think you can tell? It all depends on all the other news. Blowing through in six weeks could be a crisis and a disaster, or it could be mostly harmless and the way we wake up to a new birth of freedom

South Africa

What happened in South Africa, if this was the peak, was remarkable. They got away (mostly) clean. It certainly is suggestive of reduced severity, demographic differences can only go so far.

I count this as a pretty strong data point in favor of milder Omicron.

United Kingdom

Denmark

Around the World

China still plans to host the Olympics as far as we know, and that doesn’t seem like a great plan if they intend to go for suppression?

Anecdotally, I keep finding people saying ‘a bunch of people I know are sick, and that’s never happened before in the pandemic at once.’

Severity

Natalie Dean reads the Imperial College London paper (paper).

this is another data point in favor of a modest reduction in severity after adjusting for everything, and for Omicron being similar to the original Covid-19 in severity, as opposed to either being similar to Delta, or it being substantially milder than the original Covid-19.

Deepti has a long thread

Her core message is that exponential growth will matter more than the severity reductions if allowed to continue. And of course, that’s very right.

Severity Synthesis

I see a consistent story of a modest reduction in severity, as measured by hospitalization risk conditional upon getting a positive test.

Other

Novavax’s vaccine looks like it holds up very well against Omicron. It’s a real shame we never approved it.

Not that many hospitalizations, yet. But it’s coming. If after a week it doesn’t, that would be the other best possible news

A lab worker got infected in Taiwan, and it seems they were bitten by a lab mouse.

A note from a reader, on airports, that seems exactly right: It’s the constricted spaces that create the most risk, and we’re making little effort to increase throughput so that the lines would go away, despite it not taking much

I keep forgetting to point this out, but yes, any and all quarantines between countries, any and all travel restrictions, are pointless by now unless you’re actively containing Omicron

Predictions Update

Chance that Omicron has a 100% or bigger transmission advantage in practice versus Delta: 85% → 70%.

Chance that Omicron is importantly (25%+ in the same person) less virulent than Delta: 50% → 75%.

Chance that Omicron is vastly (75%+ in the same person) less virulent than Delta: %? → 15%.

Generation time (serial interval) of Omicron is 3.5 days or less: %? → 75%. This explains so much of what we’ve seen and makes so much sense. How else can something doubling every two days get slowed down all that much by private reactions? How could it be peaking so fast?