To his credit, JLS uses description "plahue-cured" for facility
. What we must really do is ask MM to fix the actual "ability" description. "plague - prevention" is plainly wrong.
BTW, 30 turns later my other planet was targeted by plague II. It had ~200m people (HUGE number for proporyions' type colony ! ) and I was afraid they all will expire. No, "only" 58M people die
So now I am still confused how much damage plagues do.