Check out this guide here: https://steamhost.cn/steamcommunity_com/workshop/discussions/-1/626329187083663311/?appid=246620

It should help you get an idea of what to do :)

To turn infected into dead you need to use the "additional deaths" parameter. What the parameter does not tell you, is that all those deaths always happen in the same country. The country is chosen randomly once the global requisites are fullfilled, unless you put in country conditions as well. There, you can choose wich country is it by setting the number of starting population needed, as well as other, more volatile parameters such as public order and dead/alive population. As a result of the event triggering you just put "additional deaths=999999999" or "country lethality=+9999999". As I said, these deaths always happen in a single country whenever it is triggered, so if you need to kill everybody in countries with the parameters needed, just let the event trigger endless times, if you want to indiscriminately kill everybody, you don't need to put country parameters, of course