> it'd be pointless to run a challenge trial full of low-risk individuals.
This is binary all-or-nothing thinking. It considers 90% the same as 0%, since both are not 100%.
Testing on healthy young people you learn how a normal immune system reacts to a vaccine candidate. High risk groups mostly have similar immune systems.
Even if somehow you could only vaccinate everyone under 60, that would do enormous good stopping the spread.
Another way of making the point: we did COVID challenge trials on monkeys first, because their immune systems are a decent model for that 80-year-old human's. Well, a 30-year-old human is an even better model of an 80-year-old human. A challenge trial on young people wouldn't prove everything, but it would give a high-information signal quickly.
> This is binary all-or-nothing thinking. It considers 90% the same as 0%, since both are not 100%.
Thinking is not just "binary or not"; there are degrees. If exposing that group of people would be 90% pointless, it's not much less out of the question than if it were 100% pointless.
This is binary all-or-nothing thinking. It considers 90% the same as 0%, since both are not 100%.
Testing on healthy young people you learn how a normal immune system reacts to a vaccine candidate. High risk groups mostly have similar immune systems.
Even if somehow you could only vaccinate everyone under 60, that would do enormous good stopping the spread.