[ggreer]

I'm pretty sure Robin Hanson would want challenge trials with experimental vaccines as well. The issue is that authorities won't allow such trials, not that there is a lack of willing medical experts or volunteers.

Though vaccine trials aren't quite as safe for the public as variolation. If a vaccine doesn't work, the person can spread the disease. If variolation doesn't work, then it has the same mortality as natural infection, but afterwards the person is immune and can't spread the disease.