“Immunity” and “efficacy” seem like they should refer to the same thing, but they really don’t. And if you talk to people at the FDA, or CDC, they should, and probably would, talk about efficacy, not immunity, when talking about these vaccines.
And I understand that the technical terms and usage aren’t the same as what people understand, and I was trying to point out that for technical usage, the terms don’t quite mean the things you were assuming.
And yes, the vaccines have not been proven to provide immunizing protection—which again, is different than efficacy. (But the vaccines do almost certainly provide immunizing protection for some people, just based on the obvious prior information and the current data—though it’s unclear how well they do so, at how long after the vaccine.)
And, to make things worse, even efficacy is unclearly defined. It gets defined in each clinical trial - differently for each drug/vaccine/etc. and I don’t think it actually mean the same thing for the currently approved COVID-19 vaccines. It’s pretty similar, stopping symptomatic cases, but even given the same endpoint, it’s not necessarily identical, since the studies picked how to measure the endpoints independently, and differently.
“Immunity” and “efficacy” seem like they should refer to the same thing, but they really don’t. And if you talk to people at the FDA, or CDC, they should, and probably would, talk about efficacy, not immunity, when talking about these vaccines.
And I understand that the technical terms and usage aren’t the same as what people understand, and I was trying to point out that for technical usage, the terms don’t quite mean the things you were assuming.
And yes, the vaccines have not been proven to provide immunizing protection—which again, is different than efficacy. (But the vaccines do almost certainly provide immunizing protection for some people, just based on the obvious prior information and the current data—though it’s unclear how well they do so, at how long after the vaccine.)
And, to make things worse, even efficacy is unclearly defined. It gets defined in each clinical trial - differently for each drug/vaccine/etc. and I don’t think it actually mean the same thing for the currently approved COVID-19 vaccines. It’s pretty similar, stopping symptomatic cases, but even given the same endpoint, it’s not necessarily identical, since the studies picked how to measure the endpoints independently, and differently.