@swimminginsand they also make the cure because otherwise the world just ends, if the world ends the government has nothing to govern over.
But then they also make super soldiers, so the cure either ends being destroyed along with the last remnants of government and the world ends, or the last remnants of government gets destroyed and the cure is slowly and inefficiently being distributed, but since the resources and people to make more of the cure got killed, the main way the cure is spread is by people that are immune to it just having a lot of sex.