2021-12-04/05/06 General


I referenced a preprint on Friday which said that Omicron’s doubling time was 1.2 days, but everybody else seems to be saying more like 2.5 days. This makes a difference: ten doublings (which is about 1000x) is either 12 days away or 25, which means before Christmas or after Christmas. Either way, don’t plan on doing anything after New Year’s. 🙁

Given that vaccination and prior infection do not provide extremely good protection against infection from Omicron, there’s nothing that makes me think that Omicron will provide good protection against Delta. I am starting to think of them as two different diseases.

There is a lot of anecdotal evidence that Omicron is milder, more like a cold. HOWEVER,

  • South Africa has a very very young demographic and a very high acquired immunity rate (some from vaccines, most from infection).
  • Most of the reports I have heard of infection in travellers have been in people who were vaccinated.
  • It’s early still.

AND this tweet from a South African doctor says that he has now seen two very severe cases of Omicron — so it is possible to have severe cases. Remember that even small fractions of huge numbers are large numbers.

We just don’t know. Here’s a tweet that explores the nuance.

This preprint thinks that Omicron might have stolen some of its mutants from one of the “common cold” coronavirus.

This paper reports on a simulation which predicts the level of vax evasion for thirty-three different antibodies which have been observed in recovered patients. The paper’s simulation says that Omicron will be more evasive than other variants to those 33 antibodies:

(PMS20 was an artificial pseudovirus spike which was designed to be as evasive as possible.)


Buried in this article are the factoids that you are 1.7x times as likely to die of a COVID-19 infection if you are HIV-positive, and THIRTY times more likely if you are diabetic.

Recommended Reading

This article is on HIV and COVID-19 in South Africa.

This article talks about when COVID-19 will become endemic. Apparently there is a technical definition for endemicity, which is that the rate of immunity loss (from waning vaccine effectiveness or population turnover) is equal to immunity gain (either by vaccinations or infections).

This article talks about Cathay Pacific pilots, and how — because of quarantine rules in Hong Kong — they have to spend a large fraction of their lives in quarantine.