Thread by @wanderer_jasnah

so i stumbled across this terrible article recently: boriquagato.substack.com/p/are-leaky-va… & i'm just astounded at how wrong this misinformation is, but unfortunately i'm seeing it in progressively more places.

so, thread time.

first off, it is absolutely *wild* that this person took the earlier PHE data about B.1.617.2/Delta's IFR at face value. it *never* was lower than B.1.1.7/Alpha's, it's just when you divide IFRs into >50 & <50, and all the former are vaccinated, ...

...you're going to get artifically low IFRs if you don't adjust for the fact that it's extremely age-stratified but your highest-risk group is now at much lower risk.

a more correct IFR figure would be from i.e. @DFisman's work: medrxiv.org/content/10.110…

so all the observed effect is, is better data analysis that's *still* not even correct imho, since if done correctly you'll see *high* IFRs.

which brings me to my next & most important point: severe #COVID19 is an immunopathology.

what kills you is an overactive, mistargeted immune response: ncbi.nlm.nih.gov/pmc/articles/P… -- this is unsurprising given that by the time you need to go to the ICU *you are not shedding infectious virions anymore*.

so the source of increased lethality *cannot* be immune pressure b/c by the time you're taking a turn for the worse you're past the point at which you're infectious.

so what's the *actual* cause of the increased IFRs of Alpha & Delta? very likely, replication to higher titer, faster.

namely, the changes in IFR are an *indirect consequence* of selecting for *increased transmissibility*.

finally, again, vaccines *LOWER* mutational variance: medrxiv.org/content/10.110… -- again, this is unsurprising: if variants tend to be overrepresented in persistent infections, then shortening the replicative period would be likely to have the opposite effect.

as for the many, many exasperating comparisons to Marek's Disease: it makes no sense to compare #SARSCoV2 to a DNA virus that *becomes persistent* (in lymphocytes, at that!). in fact the author of that paper has gone out against this comparison: theconversation.com/vaccines-could…

(if you're curious for more details on why the Marek's Disease comparison is deeply flawed, here's an excellent thread by @macroliter:

https://twitter.com/macroliter/status/1436733535403003907

).

anyway, vaccines are *not* going to directly increase severity of #SARSCoV2 via selection pressure whether they're sterilizing or not -- simply b/c they don't affect the virus at the correct point in its life cycle, ...

...& also b/c most of the deadliness of #SARSCoV2 *isn't* due to direct cytopathic effects.

go get vaccinated if you haven't already.