There are more formal efforts to quantify this in the literature, but that estimate, the sheer moral weight of it, compelled me to take drastic action once I saw our stats on Day 3 and extrapolated.
It's interesting that he specifically uses the word 'moral weight'. Since from what I understand there is no widely agreed upon definition of 'moral weight' on LW.
While true, that’s not actually relevant here. While LW does not have perfect agreement on exactly how morality works, we can generally agree that preventing vaccine waste is a good idea (at least insofar as we expect the vaccine to be net-beneficial, and any debates there are largely empirical disagreements, not moral ones). Nearly all consequentialists will agree (more people protected), as well as deontologists (it’s generally desirable to save lives, and there’s no rule against doing so by utilizing vaccines that would otherwise end up in the trash) and virtue ethicists (saving lives is virtuous, and it’s hardly a vice to help prevent waste; if anything it’s the virtue of frugality).
Insofar as we expect the vaccine to be beneficial (yes there’s a potential debate there, but that’s a different topic), saying that there’s a lot of moral weight here is perfectly reasonable. Consider a phlogiston theorist and a modern chemist looking at a bonfire: they might not agree on the precise nature of fire, but they can certainly agree that there’s a lot of fire present. So too here.
The opportunity cost of the resources and time they used up was not zero nor was that the only possible thing they could have done.
It only seems like the definite correct thing to do because no alternative possibilities were considered in comparison. Even within the context of saving lives during the vaccine rollout, there may have been alternative course of action that led to even more saved.
In the broader context of improving the human condition generally, the common rejoinder on LW, at least in the past, could have included things such as 'malaria nets', 'QUALYs', etc...
This line of reasoning has been discussed so many times on LW it's surprising you haven't come across it
Linked is Patrick MacKenzie's writeup of VaccinateCA, the nonprofit that succeeded at creating the best source of vaccine availability data when the government completely dropped the ball. It's long, but one of the best things I've read in a while. Some highlights:
Full link here.