All of aaqofib's Comments + Replies

Regarding the Danish hospitalization numbers:

The non-omicron variants column in the hospitalization table of the daily Danish omicron reports (which one can found on here, with the most recent one via the big "Download her" button and the older ones under "Arkiv") was changed from the previous one to the last report. Until the report from the December 15, they only reported cases for which a variant PCR test was carried out, i.e. hospitalizations of people who tested positive for coronavirus, but where no variant PCR test result is available was not counte... (read more)

The question of how much more infectious B.1.1.7 is is pretty useless without also referencing a generation time estimate. Different agencies/countries use different values for that, so the numbers for the relative R number R_B.1.1.7 / R_old they give are not directly comparable. I expanded on this in a comment a while ago.

In the meantime, the Danish SSI also published a report in which they also stress that the numbers of how much more infectious B.1.1.7 is can't be compared across countries due to in particular different generation times being used. This... (read more)

2Bucky2y
Generally true, but in using contact tracing data the English analysis is answering the "how much more infectious" question directly rather than relying on inferring from relative growth rates and estimated generation times. The 37% error does revise my estimate a bit for how confident I should be that it is <50% (although even correcting that it is probably still under 50% according to Zvi) but I still expect it to end up that side of the equation. If I was answering that survey now I'd be at 20% or so.

This is an estimated 37% increase in infectiousness. Compared to 50%, that’s much much better. The difference is enough to give us a puncher’s chance of things not being so bad, both buying us time and reducing how bad it is when the time comes.

Unfortunately, this is an incorrect conclusion from the data referenced in the tweet. It seems the 37% number was obtained by dividing 1.07 by 0.78, which rounds to 1.37. However, while 1.07 is the R of the B.1.1.7 variant, the 0.78 is not the R of the other variants, but the overall R (it says so right in the tw... (read more)

It does look like you are correct. My math from that still had it in the low-mid 40s rather than 55%, but that depends on details. If it's 55%, as I've noted before, that makes it too fast for us to stop in time unless things change fast. 

1TheSimplestExplanation2y
Good point. Do you know what portion of cases are B.1.1.7 in Denmark?

SSI (Denmark) published a new report today, that makes some of the things I talked about in the parent comment clearer.

Bilag (=Appendix) B talks about estimating the relative growth rate for B.1.1.7. On page 14 they write:

Det mest interessante er den tidslige udvikling. For hver uge øges log(odds) med 0.077 per dag. Med den nuværende lave andel af cluster B.1.1.7 svarer dette til at hyppigheden af cluster B.1.1.7 blandt de smittede stiger med 71% (95% CI: [33%, 120%]) per uge.

My translation:

The most interesting is the temporal evolution. Every week l

... (read more)

In the former control group, Sweden is throwing out the extra vaccine doses in Pfizer vials, because we might dislike the FDA but at least we don’t have to deal with the European Medicines Agency, who are totally Delenda Est Club members:

But good news, they could soon give the go ahead to stop throwing away vaccine doses.

Just for additional information / clarification, as it seems to me this could be interpreted to suggest that EU countries, after starting vaccinations on the 2020-12-27, threw away anything left over after taking 5 doses out of a vial u... (read more)

Short version: I think it comes down to different generation times used, and the Danish reports, the English reports, as well as what the referenced tweet 1 is saying are consistent with (assuming for the moment cases of the other variants stay constant) B.1.1.7 cases increasing by something like 60% to 80% each week. I would be very happy about corrections from someone who understands this better, I am not an expert at all.

Long version:

(Note: I will think about the change in infectiousness between other, old variants and B.1.1.7 as multiplicative below.)

I... (read more)

1aaqofib2y
SSI (Denmark) published a new report [https://www.ssi.dk/-/media/cdn/files/covid19/ekspertrapport_15_-januar_2021_scenarier_for_udvikling_af_covid-19.pdf] today, that makes some of the things I talked about in the parent comment clearer. Bilag (=Appendix) B talks about estimating the relative growth rate for B.1.1.7. On page 14 they write: My translation: On the next page they consider the relative contact number (=Rt) Rt_B.1.1.7 / Rt_other. They clarify that Rt is taken with respect to an assumed generation time of 4.7 days for all variants, and estimate this quotient to be Taking this to the power of 7/4.7 to get weekly rates as I did in my parent comment we would get a weekly factor of 1.58, which is different from the 71% increase per week that they had. I am not sure how to reconcile this. They write that they are using the SEIR model (which I am not familiar with) to convert between the data they consider on page 14 and the ratio of Rt's, so this might be the reason.