[mchusma]

I was a huge proponent of challenge studies in April-September 2020.

Now I don't really see the point except to build some sort of institutional process to try and make them more feasible in the next pandemic.

Moderna's vaccine was developed in Jan 2020 and in human trials in March 2020. Most of this death could have been avoided if we only could figure out how to un-ban vaccines faster. We need new approaches.

COVID was a regulatory disaster more than a biological one. Incorporating human challenge trials into the mix of things is a good thing.

[iguy]

Yes I mostly agree, it does set a good precedent, even if all it now gives us is "normal science" data.

Would like to understand better how much of the time was needed to ramp up production. My assumption was that Moderna & co. were working on that full speed, and once they'd made enough for the trials, stockpiled every dose they could make until approval.

If they'd had today's production rate in (say) April, I think we'd still have got all the deaths of the first wave. Unless, perhaps, knowing that vaccination was only a few months out would have allowed a much stronger lockdown, but I doubt it.

[tzs]

I doubt that early human challenge trials would have speed up vaccine development much, if at all. You still need the non-challenge trials to determine that a proposed vaccine is safe and effective in a large diverse population, and those are what took most of the time.

HCT trials involve people who we are either pretty sure won't get seriously ill from the virus being tested or pretty sure we can successfully treat if they do get seriously ill.

That generally means subjects who are young adults in good health with no known conditions that might put them at extra risk (and early into a new disease, we don't know what those conditions might be, so you really want to limit your early HCT to young adults in near perfect health).

The general population is full of people from children to the elderly, ranging in health from Captain America territory to Mr. Burns territory, with a plethora of already existing diseases and conditions.

Testing in that limited demographic that qualifies for an early HCT just doesn't tell you much about the safety or effectiveness of your vaccine for everyone else.