I think that's perhaps an irrelevant or tangential conclusion to draw here. You need to weigh the various options fairly. But from the perspective of mitigating the risks of "worst case" scenarios - which I think is a tricky perspective in the first place, we need to be clear which worst case perspectives are worth mitigating.
Vaccine immunity durability is not some kind of primary goal - it's several steps away from one. The risk we should be mitigating is the risk of continued pandemic spread, not the risk of short-lived immunity. That may seem like a pedantic point, but the thing is, it raises one very relevant question: how would our actions be different if we pessimistically assume vaccine-induced immunity only lasts (say) 6-9 months?
I'd argue it's likely that this makes very little difference to our actions at this point. At worst it means we'll need to scale vaccine production to a higher level, but even at that higher level the costs are trivial compared to the extra budgets already being spent to save the economy, which are themselves probably small fry compared to the actual economic damage; i.e. even in the "worst case" the costs are eminently doable; the US or EU acting alone could afford to finance vaccinating the entire world, and would even from an entirely selfish perspective probably be well served to do so - and of course, they don't need to, since other countries won't bother waiting for external help. (However, it perhaps does partially help explain Chinese vaccine diplomacy - not only is it truly helpful, it's also in their self-interest both epidemiological, and diplomatically).
But extreme pessimism isn't harmless; I think people start taking warnings less seriously when we cry wolf too frequently, and turn out to have been too cautious, i.e. wrong, in retrospect. There's little organizational benefit to assuming vaccine protection is short-lived, and it's a dishonest projection. We should be honest about the fact that we don't know how long immunity lasts, but certainly more than a few months, and potentially much longer; it could last for many years.
So sure; we shouldn't unnecessarily accept intolerable risks to society even when those are unlikely (but at least plausible) - but I don't think that's the case here.
Vaccine immunity durability is not some kind of primary goal - it's several steps away from one. The risk we should be mitigating is the risk of continued pandemic spread, not the risk of short-lived immunity. That may seem like a pedantic point, but the thing is, it raises one very relevant question: how would our actions be different if we pessimistically assume vaccine-induced immunity only lasts (say) 6-9 months?
I'd argue it's likely that this makes very little difference to our actions at this point. At worst it means we'll need to scale vaccine production to a higher level, but even at that higher level the costs are trivial compared to the extra budgets already being spent to save the economy, which are themselves probably small fry compared to the actual economic damage; i.e. even in the "worst case" the costs are eminently doable; the US or EU acting alone could afford to finance vaccinating the entire world, and would even from an entirely selfish perspective probably be well served to do so - and of course, they don't need to, since other countries won't bother waiting for external help. (However, it perhaps does partially help explain Chinese vaccine diplomacy - not only is it truly helpful, it's also in their self-interest both epidemiological, and diplomatically).
But extreme pessimism isn't harmless; I think people start taking warnings less seriously when we cry wolf too frequently, and turn out to have been too cautious, i.e. wrong, in retrospect. There's little organizational benefit to assuming vaccine protection is short-lived, and it's a dishonest projection. We should be honest about the fact that we don't know how long immunity lasts, but certainly more than a few months, and potentially much longer; it could last for many years.
So sure; we shouldn't unnecessarily accept intolerable risks to society even when those are unlikely (but at least plausible) - but I don't think that's the case here.