ZachWeems

I think there's some confusion in your discussion of variant growth rates. Moritz Gerstung and Andy Slavitt are both quoting numbers around 10% per day, which corresponds to the new/old variant ratio having a ~7 day doubling time. 

This is consistent with the CDC Nowcast.

For comparison, BA.1/Delta had a ~2.5 day doubling time, Delta/Alpha ratio about 5 days, and Alpha/wild about 12 days.

Looking at cumulative numbers per population on OurWorldInData:

As of Nov 21, Germany had performed 1001 tests per thousand people, vs 4697 for the UK.

They'd found 64.6 cases per thousand vs 144.6 in the UK.

The cumulative CFR was 1.84% vs 1.46% in the UK. Checking 3 weeks later for lag effects, Dec 12 was 1.62% vs 1.35%.

My guess is that all else equal, the UK has had a similar or higher IFR, but is catching a larger fraction of infections. In general. I'm not going to try to tease apart the differences in the current or recent situations.

Retracted: Helix changed their PCR tests. The new ones won't have an SGTF signal for this variant.

Retracting a comment on a previous post:

Previously said Helix had PCR tests that would "flag" this variant & predicted they'd give us handy graphs from this data. The company says they changed their PCR's a couple months ago, and the new ones won't flag the variant.

Omicron has the same spike protein deletion as Alpha. This deletion causes a strong 'SGTF' signal in certain PCR tests. Back when we were most concerned about Alpha, the company Helix made a page that showed what percentage of their PCR's had SGTF by date & state. Only enough data to use for CA, TX, and FL, but much more up-to-date than sequencing data.

The page seems to be deleted for now, but here is a link the company's Twitter. I expect at some point they'll announce they're doing the same thing again. https://twitter.com/my_helix

the body starts attacking the cells that produce the antigen... including the brain as polyethylene glycol goes through the blood brain barrier

How do you know what you think you know? Specifically, regarding the PEG enabling the LNP's to cross the BBB, and regarding a followup by immune cells that have crossed the BBB?

Oops, missed this. I don't check LW messages much. 

20% was not an exact value. At the time I wasn't aware of any estimates. Since then I've heard that the standard curve fit returns a ~50% growth per 6.5 days, some or all of which may be due to immune escape.)

I had a couple assumptions that made me think the SA strain was less contagious in expectation:

1. High contagiousness is more likely when high mutation numbers were seen, and correspondingly emergence would tend to be later. The SA variant gained local dominance earlier than the UK.
2. There was (and is) much less data on the SA variant. Due to the high variation in number of infectees per sick person, my prior is that on average, a variant that seems to be gaining ground is not as infectious as a curve fit implies, because luck could be a big factor and is more common than extreme fitness.

I notice I'm confused- SA's variant, if legitimately due to a huge jump in R, doesn't have huge numbers of mutations. 

If the UK variant had a 45% jump in R, and SA's has a 20%, and >20% is much more commonly due to IC'd patients, then it seems reasonable that the super-fit, highly mutated strains show up alongside the more mundanely fit, moderately mutated ones. The super-fit's take longer to bake but they take off faster. But then again I'm trying to make a theory to explain 2 data points that I'm not 100% are both correct, so as much as this feels correct it probably isn't.