Just_a_fan wrote: ↑01 Feb 2021, 16:31
It's worth bearing in mind that many vaccines have remarkably low effectiveness in terms of the % protected.
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It's about reducing severe symptom numbers to a low enough level that the health system can cope whilst also being able to offer the normal everyday health services.
That's true enough of course, but there are a couple of flies in the ointment, IMO, which means I think climbing out of the rather deep hole the UK (for example) is in right now will take time.
The IFR is so massivly different per age that the while what you say is true in aggregate wrt. efficacy through the population, what seems to be more valuable from a policy making and hospital utilisation perspective is the efficacy in elderly cohorts.
Onto that one somehow grafts the conventional heuristic is that if everyone is vaccinated enough, everyone is protected quite a bit because the virus can't move through the general population freely.
As you see many countries are (rightly so) vaccinating the more risky elderly cohorts first BUT - they are not drivers of infection population wide, because the most vulnerable are not interacting and spreading the virus as much, so their vaccination will not slow the spread in aggregate population. It will however, stop the elderly from getting infected/sick. So to square this circle here, efficacy in this cohort matters to hospital utilisation multiplicatively more because of the skewed IFR.
So I agree with you in principle that efficacy doesn't need to be super high here, but perversely in this current political/risk/epidemiological climate, it ends up IMO mattering quite a bit more than in 'normally would'.
I think a lot of people are waiting for the cases and new hospitalisations statistics for Israel in January to be completed (for example
https://www.science.co.il/medical/coron ... on-age.php and others). There have been some rumours of it going well, but if it was going perfectly I think there would have been more people screaming the good news from the rooftops.