Alberta vaccine effectiveness update
I figure it might be interesting to do some smaller posts as I get busy throughout the week. Again, I have gone over the various problems with vaccine effectiveness especially with a lack of controls, but I thought it might be interesting to report some of the real numbers. I expect all of these numbers would be lower when controlling for confounding variables (and have little reason to expect them to be higher).
These numbers are over the previous two weeks in Alberta, Canada.
First dose less 14 days: -48.53%
First dose overall: 33.33%
Second dose less 14 days: 67.18%
Second dose overall: 75.02%
As I have previously mentioned, people are more likely to get the virus in the period after they take the vaccine. This has probably driven recent waves, and I expect the number to jump when they begin to vaccinate children due to the cohort effect (many people with weakened immune systems interacting with eachother).
The true first dose vaccine effectiveness is about half of what is reported: this number is likely higher as it seems to be dominated by people that have had the first dose for a while and may have been previously exposed.
The second dose less than 14 days is a large jump, though I expect most people at that point are still not at the breakeven point from the effect in the first dose and this may partially be driven by acquired natural immunity (both from the first dose, and the fact that many previously exposed people were required to get vaccinated for work).
The second dose vaccine effectiveness is impressive. I wonder if this will begin to decrease as the larger proportion of the population with vaccines are beginning to inch towards the 6 month mark.
Booster effectiveness was impossible to calculate due to an opaque data set (I have an idea of where it is hidden but I do not want to do any guesswork).
Sorry for the rough data — if I had a better dataset, I’d have better calculations!