I think they planned to leave only 1 billion people left alive not kill 1 billion people, and theven people who caused it are still human and can probably get infected plus the civilians that are left Olso need a cure so not to get infected
Their initial population was 7+billion, what they want is to reduce it to 1 billion, that's why they planned to kill all the infected(8+% of the population). But killing the infected doesn't mean getting rid of the disease since they don't know the initial cause of the infection, that is why they needed the doctor to create the cure so that the remaining 1 billion can be safe against the infection.
Ye
wait so you want to kill one billion people... and then get mad at the lady for destroying the cure?? the cure against the thing that you caused in the first place?? i’m confusion