Human Challenge Trials aren’t riskier than Randomized Controlled Trials

Saturday, November 23rd, 2024

Keller Scholl, who spent time at GMU working with Robin Hanson and hanging out with the gang, just came out of quarantine from a Human Challenge Trial:

Scholl’s symptoms might be uncomfortable, but they are also of his own making. That’s because he signed up to be a volunteer in the first human ‘challenge trial’ involving Zika virus, a mosquito-borne pathogen that can cause fever, pain and, in some cases, a brain-development problem in infants. In standard infectious-disease trials, researchers test drugs or vaccines on people who already have, or might catch, a disease. But in challenge trials, healthy people agree to become infected with a pathogen so that scientists can gather preliminary data on possible drugs and vaccines before bigger trials take place. “Accelerating a Zika vaccine by a month, a few days, that does a lot of good in the world,” says Scholl, who studies at Pardee RAND Graduate School in Santa Monica, California.

Alex Tabarrok reminds us that Human Challenge Trials aren’t riskier than Randomized Controlled Trials:

The rest of the article uncritically repeats the usual claims from so-called “bioethicists” that human challenge trials (HCTs) are unethical because they involve risks. Of course, HCTs carry risks—so what? Randomized controlled trials (RCTs) also require that participants are exposed to risk. Indeed, for participants in the placebo arm of an RCT, the risks are identical. Furthermore, since RCTs require more participants to achieve statistical validity than HCTs, they must expose more people to harm and, as a result, it’s even possible that more participants are harmed in an RCT than an HCT. Thus, HCTs are not necessarily more risky to participants than RCTs and, of course, to the extent that they speed up results, they can save many lives and greatly reduce risk to everyone else in the the larger society.

In my talk, The Economic Way of Thinking in a Pandemic (starting around 10:52, though the entire presentation is worthwhile), I explain the real reason why bioethicists and physicians hesitate over human challenge trials: they fear feeling personally responsible if a participant is harmed. “We exposed this person to risk, and they died.” Well, yes. But my response is, it’s not about you! Set aside personal emotions and focus on what saves the most lives.

Comments

  1. T. Beholder says:

    So many of this. Starts sensible, then veers into ”utilitarianism good, personal responsibility bad”.

  2. McChuck says:

    Perhaps Mr. Tabarrok should volunteer himself for the next Ebola vaccine trial? After all, it’s “safer” than waiting for some poor village to contract it naturally. And it’s for “the greater good”.

    Doctor Mengele had this same belief, and the political apparatus to act upon it. We still use his medical data, so what he did must have been ethical, good, and morally right, wasn’t it?

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