Yeah. Just keep telling me the vax is effective. Sure, I'll believe you eventually. Uh-huh.
https://www.cnbc.com/2021/07/30/cdc-study-shows-74percent-of-people-infected-in-massachusetts-covid-outbreak-were-fully-vaccinated.html
No argument for or against the vaccine from this data. in terms of judging the efficacy of the vaccine, this is nonsense. Literal noise. I believe it's an example of Simpsons paradox. Yet it's been a hobby of the media to post the % of hospitalized people as if it's meaningful, fully knowing that their readers will not be able to draw correct conclusions from the numbers. If there were any accountability (ha!) they would be punished for posting these numbers at all.
You cannot judge vaccine efficacy by % of hospitalized people that are vaccinated. You also need to know something (a lot actually) about the vaccine rates in the population, and also specifically in the sub-population coming in for hospitalization.
If we had a city with 100.0% vaccination rate and the vaccine was say 99% effective we might still have people coming into the hospital, and by definition 100% of the hospitalized people would be vaccinated. It doesn't mean anything against the efficacy of the vaccine.
Similarly if we have 80% of a certain city vaccinated but the 20% of the population that's not vaccinated are all black, let's say for example, and everyone being admitted to the hospital is black, technically we will have 100% if the people hospitalized being unvaccinated, and technically that doesn't mean the vaccine works either! It could be that the vaccines are actually sugar water, and totally ineffective, and it just so happens that the outbreak is happening around people that are vaccinated at a lower rate than the general population, and the people who are vaccinated are all working from home or something, so they aren't getting it. You literally cannot tell much from %hospitalized who are vaccinated alone.
For the record, I think the vaccines seem pretty effective. Recently Cleveland clinic published that 99.7% of its hospitalizations were unvaccinated, and the overall vaccination rate for Ohio is/was about 45%. To me this is a strong indicator that vaccines are working but it proves nothing by itself and we would need to know a lot more about how vaccines are distributed in the population at large, a lot more about how the hospitalized population demographics and contact patterns, and mixing patterns within the two. Some studies show very limited physical mixing between political factions and between classes, and also we can assume distribution of vaccines is similarly split between political factions and classes. So if the highly vaccinated people are just staying away from the unvaccinated people then it can explain why we might see one hospital with 99% unvaccinated admissions and one hospital with 84% vaccinated admissions.
What matters is what are my chances of the vaccine protecting me. The best data is a controlled study which was done with about 40,000 randomized, placebo controlled people during the vaccine trials, which showed good effectiveness, like essentially 100% against death, 90%+ for hospitalization and 70% for getting symptoms but all the vaccines are slightly different. The question is what is it against delta variant now and I think we need another controlled trial to know.
