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I haven't checked in a while, but does the data show that the efficacy against delta is less than the 90% we thought the vaccines were going to be?

I mean, we all knew some vaccinated people would still get Covid, about 10% of them, so do we know that there is a higher number of breakthrough cases than even that?

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sure we did. that ~90% number came before the south African variant, and many others. that's arguably why the j&j had a much lower rate than Pfizer, as it was tested amongst test pools with different variants circulating.

> that's arguably why the j&j had a much lower rate than Pfizer, as it was tested amongst test pools with different variants circulating.

J&J was tested in populations that didn't have the SA variant, and Pfizer was tested in populations that did (in addition to the other combinations you mentioned). Tests were done worldwide and we had natural experiments due to different tests in different time in different (relatively) isolated populations.

That effect exists, but only covers a small percentage of the difference in efficacy.

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