Wild speculation, not an expert. I’d love to hear from anyone who actually knows what’s going on.
I think it’s overoptimistic that human challenge trials would save a year, though it does seem like they could have plausibly have saved weeks or months if done in the most effective form. (And in combination with other human trials and moderate additional spending I’d definitely believe 6-12 months of acceleration was possible.)
In terms of why so few human experiments have happened in general, I think it’s largely because of strong norms designed to protect experiment participants (and taken quite seriously by doctors I’ve talked to), together with limited upside for the experimenters, an overriding desire for vaccine manufacturers to avoid association with a trial that ends up looking bad (this doesn’t apply to other kinds of trial but the upside is often lower and there’s no real stakeholder), a lack of understanding for a long time of how big a problem this would be, the difficulty of quickly shifting time/attention from other problems to this one, and the general difficulty of running experiments.
Why did nobody in the world run challenge trials for the covid vaccine and save us a year of economic damage?
Wild speculation, not an expert. I’d love to hear from anyone who actually knows what’s going on.
I think it’s overoptimistic that human challenge trials would save a year, though it does seem like they could have plausibly have saved weeks or months if done in the most effective form. (And in combination with other human trials and moderate additional spending I’d definitely believe 6-12 months of acceleration was possible.)
In terms of why so few human experiments have happened in general, I think it’s largely because of strong norms designed to protect experiment participants (and taken quite seriously by doctors I’ve talked to), together with limited upside for the experimenters, an overriding desire for vaccine manufacturers to avoid association with a trial that ends up looking bad (this doesn’t apply to other kinds of trial but the upside is often lower and there’s no real stakeholder), a lack of understanding for a long time of how big a problem this would be, the difficulty of quickly shifting time/attention from other problems to this one, and the general difficulty of running experiments.