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the qatar study on relative breakthrough rates in the vaccinated
recovery from covid is what looks most effective
almost everyone is misreading THIS STUDY which is, frankly, kind of a junk study that’s answering a question no one really asked.
so let’s talk for a minute about what it does and does not show.
this was a BIG study. it had over 450k subjects selected and matched from ~1.5 million. only those dose 2 + 14 days and after were considered “vaccinated”.
astonishingly, what it did not have was any of the relevant control arms to actually assess vaccine efficacy (VE). they did not even try.
they measured and matched no unvaccinated people at all.
it’s not really clear to me what the point of this whole exercise was. all it showed was this:
it did not show that vaccines do or do not work. no claims on that can be made from this data.
this is the chart everyone seems to be obsessing over. it shows one thing and one thing alone: that having had covid and then getting vaccinated makes you MUCH less likely to get covid in the future.
it looks to be about 80% less and this is consistent across both vaccines. both pfizer (top) and moderna (bottom) were about 5X the infection rate of vaccine + prior infection. they are just scaled differently.
but, because we have no base rate to comp this to vaccines or both could have made it worse for all we know. maybe they made it better.
but why you would do this and not measure that? #baffled.
what it probably DOES show is proof of vaccine fade. the vaxxed curves start steepening in slope over time. if that were a function of base prevalence, both lines would do so. but they don’t. those with prior covid do not get this effect.
so, it looks like the most effective, most durable booster for vaccines remains “actual covid.” this data shows the same wane we see HERE where the fade slope started getting steep around 90 days, just like moderna above and similar to pfizer that might be more like 110.
additionally, the scaling seems to be confusing people.
contrary to what many are saying this does NOT prove that moderna works better. it said so right in the first page of the study (shown above).
the cohorts were not matched to support a claim like that. we do not know the base rate in the groups.
again, i really am sort of baffled by what the point of this study was. further, the limitations of it are significant and the matching looks, frankly, terrible.
comorbidity is the single largest driver of covid outcomes and has a full log or greater effect. you can see that HERE. in high risk groups, it’s basically a 2 log drop. (99%) in risk if you have no comorbidities.
claims that comorbidities are rare in qatar are absurd. they are one of the most obese, least healthy nations on earth. 70% are overweight/obese. exercise is rare. fast food is common. vitamin D deficiency is rife. 1/3 of adults are hypertensive. 17% have diabetes.
every one of these things is a risk factor.
and the presumption that being high risk might be what leads to getting vaxxed even if you’ve already had covid seems a reasonable guess on bias, esp as the study dates back to december 2020 and the high risk were going first.
frankly, this all looks like a mess.
we’ve seen piles of data showing that vaccines appear not to stop infection and are actually associated with higher, not lower rates overall.
but this does not even speak to that, just that having had covid pre vaxx is an 80% risk reducer on cases going forward.
we have no idea if that outperforms natural immunity alone. given many of the numbers on that i doubt it. natural immunity seems to be at least 5X and possibly 27X as potent in terms of case prevention as vaccinated. that would make an 80% drop vs vaxx a push at the low end and inferior toward the higher end. (and there are reasons to suspect vaccination might interfere with natural immunity)
so, i’m kind of baffled this study is getting so much play.
it shows quite little, is of very low quality with lots of possible confounds that seem blithely handwaved away, and looks to be answering a question no one really asked.
honestly, i’m left pretty surprised that anyone spent the time to do this.
it wasn’t even that fun to bat around.