I had been hearing that Omicron had a doubling rate of something like 5 days. I finally went and scraped the data for Guateng province — which is only like two-thirds Omicron right now — and calculated a doubling time of 3.1 days.
Then this preprint came out (which probably has information about just the Omicron cases) and it says that the doubling time is 1.3 days. Holy f, that’s fast. That means if we had 50 cases in Canada on 30 November, we have 400 today. If unchecked, that would be 52M in Canada by Boxing Day (which is obviously not possible). YIKES!!!
I should note that this source estimates 3.3 days, but I have a hard time seeing how doubling could be slower than the 3.1 days that my calculations showed.
I misspoke slightly in yesterday’s post about the big COV-BOOST study. I said that the more mRNA the better, but there was one case where that was not true. Pfizer/Pfizer + AZ had a little stronger T cell response than Pfizer/Pfizer + Pfizer, and slightly stronger T cell response than Pfizer/Pfizer + Moderna.
Still, it was striking to me how consistently better the mRNA vaccines are than the non-mRNA vaccines in short-term measures.
There’s some evidence that the J&J is more durable (like see this article), but what we know right now is that one shot starts out crappy and stays at the same level of crappy. (We don’t have good info on long-term effectiveness of two shots of J&J yet.)
This article reports that NACI now recommends boosters for everyone over 50 and says that people under 50 may be offered boosters depending on where they live and their circumstances.
NACI says that because there are fewer cases of myocarditis with Pfizer than with Moderna, if young men are going to get boosters, they should get Pfizer.
This Comment reports that in a highly (90.3%) vaccinated area, vaccinated patients admitted to hospital with COVID-19 had milder cases than the unvaccinated, despite being older on average, with more significant co-morbidities. Yay vaccines!
This preprint says that about a quarter of people don’t get good antibody levels after two doses of mRNA vaccines, but they do after a third dose.