5 ms·

> E.g. israeli data which I am intimately familiar with is incredibly biased Can you expand on this? Why is the data biased by demographics? Is this data bias

• beagle3 5y ago
  > Is this data biased in the same way as the other countries that show a 90% effectiveness? Well, Israeli MOH rules are basically that unvaccinated people must test at least twice a week to continue normal life, whereas vaccinated people need not test even while showing symptoms, even when being admitted to a hospital ; This had variation over time (e.g., since Jan 2021, approx 8 months only unvaccinated had to test on hospital admission, and 4 months everyone), but that's the gist. Furthermore, upon exposure to a verified case, the vaccinated can do a home test, and self report that they are negative, and not quarantine - whereas the unvaccinated must quarantine, and test in an offical supervised test, twice in a 7-day period in order to finish quarantine after 7 days, or spend 14 days in quarantine if they do not want to test. (This was shortened to 5 days last week, and also had some variations over time, but same gist). There are many other biases. It's kind of ridiculous. I don't know exactly how other countries run these things, but I suspect it's similar in other places, though the details differ. >> while at the same time airport data which is the only place with unbiased testing showed about 60% > Link? https://papers.ssrn.com/sol3/papers.cfm?abstract_id=3963606 https://papers.ssrn.com/sol3/papers.cfm?abstract_id=3963606 It's biased by economical demographic traits, because the people who actually fly are not a representative sample; But since everyone who lands gets tested, there is no bias such as the ones I described above. (Well ... there is; a vaccinated person tests once on arrival and that's it; an unvaccinated person must test again in 10 days, and if positive in the 10-days after arrival is considered to have been postiive on arrival -- but compared to the above, this is a "small" bias). > Only because they haven't done an RCT that could possibly pick that up, Well, yes, but there isn't one. As I said, it cuts both ways - they haven't done a test that's powered enough to show vaccine ACM is worse than placebo ACM. Is that the only reason it doesn't exist? Maybe yes, maybe not. Cuts both ways. Are you familiar with Fenton & Neil's work? https://probabilityandlaw.blogspot.com/2021/11/is-vaccine-efficacy-statistical-illusion.html https://probabilityandlaw.blogspot.com/2021/11/is-vaccine-ef... https://probabilityandlaw.blogspot.com/2021/12/the-impact-of-misclassifying-deaths-in.html https://probabilityandlaw.blogspot.com/2021/12/the-impact-of... They also have academic level papers, but the blog posts are short and concise.
  • csee 5y ago
    > [bias in VE for hospitalization] Well there's no such bias in Australia, AFAIK. Everyone has the same testing requirements. Let's forget vaccine effectiveness (VE) against hospitalization, because as far as Israel is concerned you may be right. What about VE against mortality? How could this data be biased? I always focus on VE against mortality, since it's the least prone to bias. (EDIT: I see your link to Fenton & Neil, I will discuss below) > [Airport testing] That's interesting, but there are other explanations for this. For example, natural immunity in a large % of the 'unvaccinated' population by the time that this study was done. Another explanation could be old people self-selecting into the vaccinated population. That will again make vaccines seem weaker than they are in reality, especially in their ability to prevent infection. I also note that the RCT which you like showed strong VE against infection (against an old variant). > Is that the only reason it doesn't exist? Probably yes? And if not, it's probably some other basic explanation, such as Pfizer not wanting to waste their own money on a trial if the FDA didn't require it. They are for profit, after all. Is there a need for some deeper reason? Occam's Razor. > Fenton & Neil's work Interesting. Maybe this bias existed in that ONS report at a particular time period, I didn't read the full report, it's quite long. Maybe this bias exists in all the data sets being reported by different countries. It's possible. But what about the VE against mortality in countries that have plateued vaccination rates, where such a bias is going to be minimal? Wouldn't we find evidence of a sharp drop in VE over a rolling 4-8 week window? Can anyone show me this happening to any of the big countries? If someone can show me that - and the data public in a number of countries, so it should be possible to show - I will probably change my mind.
    • beagle3 5y ago
      > What about VE against mortality? How could this data be biased? At least two ways: (a) Fenton & Neil trick in the blog posts I linked - it applies to any measure. Note that people who died in the first 28 days post original shot are considered unvaccinated, despite all tests showing very significant antibody response in 12 days. (b) Ignoring all cause mortality. Taken ad absurdum: Inject cyanide. 100% efficiency against corona death. Step back from absurdum: it's possible the vaccine induces "silent covid" by generating the spike but failing the PCR tests -- so that, in fact, as far as mortality goes, it is equivalent to getting sick, but as far as testing goes, it's never attributed to covid. > That's interesting, but there are other explanations for this. Yes, there's always other explanations for everything. You reach your conclusions because of your prior, which is "the vaccine is effective, let's see how and why". Which is fine, but you should acknowledge your prior rather then assume it is universal. I have a less informative prior, and the data is much less convincing under that prior. > They are for profit And have already paid billions of dollars in fines for past "for profit against health" actions. BMJ editor Peter Doshi has shown -- as soon as they've published -- that equally valid interpretations of Pfizer's own data can show 29% effectiveness. Now, there are two ways to interpret the data - one shows 95% effectiveness against mild disease (and no information about severe disease), and one shows 29% against mild disease (and no information about severe disease). Which one do you expect a for-profit company to champion? > But what about the VE against mortality in countries that have plateued vaccination rates, where such a bias is going to be minimal? Wouldn't we find evidence of a sharp drop in VE over a rolling 4-8 week window? Can anyone show me this happening to any of the big countries? It is, in fact, the current narrative, that vaccine efficiency drops significantly after 4 months or so, and that's why a booster shot is needed (Israel has already been administering the 4th shot for a month, Fauci is talking about doing same in the US). It is strictly in the negative territory for mild disease now, still positive (but dropping) for severe disease and mortalitly. Some of it is blamed on immune escaping variants, but the dropping VE is seen everywhere. Don't have the links handy, but that's why they are boosting, officially.