I think it could be very useful if, say, we get a vaccine, but don't have near enough supply to vaccinate everyone. By knowing who is at most risk, we could ta

I think it could be very useful if, say, we get a vaccine, but don't have near enough supply to vaccinate everyone. By knowing who is at most risk, we could target a limited supply to who is most at risk. This would be the opposite of normal thinking, which is to vaccinate the healthy people so that the unhealthiest don't have to get vaccinated, since any vaccine has some small chance of being problematic if you've already got issues. But, in this case, if we cannot produce enough vaccine fast enough, it could be that targeting those most at risk would be the right call.