Thanks for sharing. Just to make it clear, I am in full agreement that covid vaccines are very effective at reducing covid infection severity, especially in older age groups. The document we are discussing confirms as much.
> simply because a larger proportion of the population are vaccinated than unvaccinated and no vaccine is 100% effective.
They are computing case rates. This part of the argument doesn't explain that the case rates are similar in vaccinated vs unvaccinated population.
> This is especially true because vaccination has been prioritized in individuals who are more susceptible or more at risk of severe disease.
The cumulative vaccination uptake rates are 85%+ in >50 ages group, see charts on pages 9-10. While prioritization may have a sizable effect at small vaccination rates, once almost all of the population is vaccinated we have to assume the most of the vaccinated are not 'more susceptible or more at risk of severe disease', otherwise we are simply saying that (almost) everyone is more susceptible. Also, it is 'susceptible of severe disease' not simply 'susceptible of getting infected with covid'. If 10-15% of the population were to have 90% smaller susceptibility to covid infections within the same age group from natural causes, we would have heard about that by now.
For me, the mystery remains.
I could speculate a number of hypotheses, the first one being that there is something about they count 'covid cases' that doesn't match the rest of the literature, but I was unable to find the specific paragraph describing that. Perhaps there is something really dumb that escaped me :(
On the flip side, I also don't have visibility in how 'vaccine effectiveness' rates are computed in the rest of the literature. Perhaps there is something about how other people count 'covid cases' that presents a different picture.
That being said, theirs is a real life measurement of an entire country on natural timeframe, vs. studies that are usually done on population samples on limited timeframes, and then extrapolated to entire countries on natural timeframe. So while this is a single source, it is from a highly credible org with a highly credible setting, making it difficult to dismiss offhand.